Acute Warm-up Effects in Submaximal Athletes

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Copyright © 2015 American College of Sports Medicine

Acute Warm-up Effects in Submaximal Athletes:

An EMG Study of Skilled Violinists

J. Matt McCrary

1, Mark Halaki

2, Evgeny Sorkin

3, and Bronwen J Ackermann

1

1School of Medical Sciences, Sydney Medical School, The University of Sydney,

Sydney, NSW, Australia; 2Discipline of Exercise and Sport Science, The University of

Sydney, Sydney, NSW, Austrailia; 3Sydney Conservatorium of Music, The University of

Sydney, Sydney, NSW, Australia

Accepted for Publication: 17 August 2015

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Copyright © 2015 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.

Acute Warm-up Effects in Submaximal Athletes: An EMG Study of Skilled

Violinists

J. Matt McCrary1, Mark Halaki

2, Evgeny Sorkin

3, and Bronwen J Ackermann

1

1School of Medical Sciences, Sydney Medical School, The University of Sydney, Sydney, NSW,

Australia; 2Discipline of Exercise and Sport Science, The University of Sydney, Sydney, NSW,

Austrailia; 3Sydney Conservatorium of Music, The University of Sydney, Sydney, NSW,

Australia

Corresponding Author

J. Matt McCrary

University of Sydney, Cumberland Campus

PO Box 170

Lidcombe, NSW

Australia, 1825

+61 2 8880 0199

[email protected]

This work was supported by the Australian-American Fulbright Commission and an Australian

Research Council Linkage Project Grant (LP0989486). The authors declare no conflicts of

interest. The results of this study do not constitute an endorsement by the American College of

Sports Medicine.

Running title: Acute warm-up effects in skilled violinists

Medicine & Science in Sports & Exercise, Publish Ahead of PrintDOI: 10.1249/MSS.0000000000000765

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NonCommercial-NoDerivatives 3.0 License, where it is permissible to download and share the

work provided it is properly cited. The work cannot be changed in any way or used

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ABSTRACT

BACKGROUND: Warm-up is commonly recommended for injury prevention and performance

enhancement across all activities, yet this recommendation is not supported by evidence for

repetitive submaximal activities such as instrumental music performance. PURPOSE: Quantify

the effects of cardiovascular, core muscle, and musical warm-ups on muscle activity levels,

musical performance, and subjective experience in skilled violinists. METHODS: Fifty-five

undergraduate, postgraduate, or professional violinists performed 5 randomly ordered 45-second

musical excerpts of varying physical demands both before and after a randomly assigned 15-

minute, moderate intensity cardiovascular, core muscle, musical (technical violin exercises), or

inactive control warm-up protocol. Surface EMG (sEMG) data were obtained for 16 muscles of

the trunk, shoulders, and right arm during each musical performance. Sound recording and

perceived exertion (RPE) data were also obtained. Sound recordings were randomly ordered and

rated for performance quality by blinded adjudicators. Questionnaire data regarding participant

pain sites and fitness levels were used to stratify participants according to pain and fitness levels.

Data were analyzed using 2 and 3-factor ANCOVAs (sEMG and sound recording), and

Wilcoxon matched pairs tests (RPE). RESULTS: None of the 3 warm-up protocols had

significant effects on muscle activity levels (p≥0.10). Performance quality did not significantly

increase (p≥0.21). RPE significantly decreased (p<0.05) following warm-up for each of the 3

experimental warm-ups; control condition RPE did not significantly decrease (p>0.23).

CONCLUSION: Acute physiological and musical benefits from cardiovascular, core muscle,

and musical warm-ups in skilled violinists are limited to decreases in RPE. This investigation

provides data from the performing arts in support of sports medical evidence suggesting warm-

up only effectively enhances maximal strength and power performance. KEY WORDS:

PERFORMING ARTS MEDICINE, ATHLETES AND THE ARTS,

ELECTROMYOGRAPHY; MUSCLE ACTIVITY

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INTRODUCTION

Warm-up prior to the start of physical activity is commonplace in both athletics and the arts, and

is advocated by leading texts for its potential for injury prevention and performance

enhancement in both athletic (10) and musical (24) contexts. Recent reviews, however, have

demonstrated that warm-up benefits are more nuanced than anecdotal evidence might suggest (6,

26). Furthermore, there are no investigations of warm-up effects on submaximal activities

outside of steady-state endurance exercise (9). Elite instrumental musicians are submaximal

athletes, performing highly repetitive movements with mean heart rates as high as 72% predicted

heart rate maximum over the course of a performance (20); these physical demands have been

recognized by the American College of Sports Medicine‘s Athletes and the Arts initiative. Daily

training of 6-8 hours causes a high incidence of overuse injuries—career injury incidence for

symphony musicians is reported as high as 81.3% (1). Determining the effects and mechanisms

of warm-up in instrumental musicians is a vital first step towards informing whether warm-up

fits into evidence-based injury prevention programs for instrumental musicians and other

submaximal athletes.

Comprising the largest proportion of most orchestras, violinists are a logical starting place for

investigation of warm-up effects in instrumentalists. Study of violinists was further encouraged

by a relatively standardized instrumental set-up, use of both small and dynamic movements, and

prior physiological investigation into violin performance using surface electromyography

(sEMG) (2, 32). This prior sEMG study of violinists has largely focused on bilateral analysis of

upper trapezius muscles, with a maximum of 8 shoulder, neck, and right arm muscles

simultaneously recorded (32). With technological advances allowing simultaneous wireless

recording of 16 sEMG channels, more comprehensive analysis of muscle activity involved in

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arm movements of the shoulder, upper arm, and forearm is now possible. In addition, prior

research indicating core stability reduces injury risk (23) affords particular importance to the

inclusion of core musculature in investigations of potential warm-up related injury prevention

mechanisms.

In any performance-related physiological quantification of warm-up effects, measurement of the

impact of the intervention on musical performance and subjective experience is essential in

obtaining comprehensive measurement of warm-up effects. Regardless of any physiological

benefit, absence of concurrent benefit to either performance and/or subjective experience is

likely to significantly reduce adherence to any intervention (35).

Accordingly, the purpose of this study was to quantify the effects of a variety of warm-ups

(cardiovascular, core muscle, and musical) on muscle activity, musical performance, and

subjective experience in violinists. SEMG, sound recordings, and survey data was measured

during the varied physical demands of violin performances. This tested anecdotal evidence and

current pedagogical and health recommendations by recording effects of the three active warm-

ups on all three outcomes.

METHODS

Participants

Inclusion criteria were university (either undergraduate or postgraduate) or full-time professional

violinists. Participants (n=55; 15 male/40 female; 17 professional/3 postgraduate/35

undergraduate; age = 28.2±12.3 years) were recruited from university music schools and

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professional orchestras in 8 cities across Australia and New Zealand. Age did not significantly

differ between experimental groups. The protocol was approved by the University of Sydney

Human Ethics Committee prior to study commencement (HREC # 2013/869) and all participants

gave written informed consent prior to participation in this study.

Pre-Test Power Analysis

Power analysis was performed using the results of a prior surface EMG based investigation of

warm-up from sports medical literature that most closely mirrored our study design (36). Pre-

and post-warm-up gastrocnemius activity values were used (pre: 123.6±16.83 mv; post:

145.7±17.1 mv), resulting in an effect size (Cohen‘s d (12)) = 1.3532. A priori power analysis

was conducted in G*Power 3.1(16) using an independent means test (β=0.8, α=0.05); this

analysis revealed that 8 subjects per group are required to observe specific effects. Given the

novel nature of this investigation, additional subjects (n=12-16 per group) were recruited to

maximize statistical power.

Overview of Testing Protocol (Figure 1)

All eligible participants were scheduled for a single 2-hour research appointment. Participants

were instructed to refrain from playing their instrument or exercising for the 12 hours preceding

testing to avoid warm-up effects from these activities. At the beginning of the testing period,

participants completed a pre-test questionnaire and physical self-assessment. Based on responses

to the questionnaire and assessment, participants were randomized in a stratified manner into

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warm-up groups. Surface electrodes and wireless transmitters were applied to 16 muscle sites.

Participants performed 5 short, randomly ordered musical excerpts both before and after their

randomly selected warm-up protocol: cardiovascular, core muscle, musical, or inactive control.

Ratings of perceived exertion (RPE) were taken following the pre and post warm-up

performances. During performances of the excerpts, sound and sEMG were recorded. Sound

recording data were adjudicated by an expert jury of professional violinists not affiliated with the

study, and sEMG data were analyzed by study personnel blinded to participant warm-up

condition. Following the excerpt performances, participants completed a post-test questionnaire

and maximum voluntary contraction (MVC) protocol for all investigated muscles.

Surface Electromyography

Selection of Muscles for sEMG Analysis

A focus was placed on right arm muscles, based on data from Shan, Visentin, and Schultz (32)

indicating that right (bowing) arm movements have the largest amplitudes and velocity during

violin performance. For the bowing action, the following muscles were selected for analysis:

right biceps brachii, triceps brachii (lateral head), pectoralis major, anterior deltoid, posterior

deltoid, upper trapezius, lower trapezius forearm flexors, and forearm extensors. Left trapezius, a

common site of tension and injury in violinists (7, 28), was also analyzed, as well as six muscles

of the core musculature: right and left upper abdominals, right and left lower abdominals, erector

spinae (L1/T12).

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Preparation of Skin and Placement of Electrodes

Prior to placement of electrodes, skin was prepared through vigorous rubbing with alcohol and

abrasive gel (NuPrep, Aurora, CO, USA) to reduce impedance. Electrodes were placed according

to the methodology of SENIAM (31) (right and left upper trapezius; right lower trapezius; right

anterior deltoid; right posterior deltoid; right and left erector spinae (L4); right biceps brachii;

right triceps brachii (lateral head)) or, for muscles for which SENIAM did not make placement

recommendations (right forearm flexors; right forearm extensors; right pectoralis major; right

and left upper abdominals; right and left lower abdominals), electrode placements were as per

Criswell (13). Two Ag/AgCl surface electrodes (Red Dot, 2258, 3M, Sydney, NSW, Australia)

were placed 2 cm apart in parallel with the muscle fibers of each selected muscle/muscle group.

Fixomull hypoallergenic adhesive tape (Smith & Nephew, North Ryde, NSW, Australia) was

applied as needed to prevent movement of electrodes during trials. Electrodes were connected to

wireless EMG sensors (Noraxon, TELEmyo DTS EMG sensors, Scottsdate, AZ, USA – ~14

grams, 3.4x2.4x1.4 cm with 1st order band pass filter 10 - 500 Hz, gain of 500, input impedance

> 100 MΩ, CMR > 100 dB). The signals were transmitted to a 16-bit resolution receiver

(Noraxon TELEmyo DTS belt receiver, Scottsdate, AZ, USA) and saved to a computer at a rate

of 1500 Hz using the MR3 software (Version 3.6.20, Noraxon, Scottsdate, AZ, USA).

Recording of Violin Excerpts

All excerpts were recorded using either a Zoom H4N Handy Portable Digital Recorder (Zoom,

Tokyo, Japan) or iPhone 4 internal microphone (Apple Inc., Cupertino, California, USA); with

the same device used for each participant‘s trial. One participant did not consent to audio

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recording, resulting in audio recordings for n=54 participants. Audio recordings from the two

recording devices were edited using Garage Band software (Apple Inc., Cupertino, California,

USA) to align the beginning and end of each recording with the start and finish of each excerpt

performance. Additionally, care was taken to match overall volume levels, background noise

levels, and the mix between the violin performance and metronome across all recordings.

Adjudication of Violin Excerpts

A separate audio file was created for each performance (i.e. pre- & post-warm-up) of each

excerpt. These audio files were randomly ordered and sent to two experienced violin

performance adjudicators with no affiliation to the study. Duplicate recordings (n=20) were

included to ensure reliability of adjudication. Each separate audio file was adjudicated using a

standard violin performance rubric including intonation accuracy, tone clarity, and overall

impression (see Document, Supplemental Digital Content 1, full adjudication rubric,

http://links.lww.com/MSS/A563). A score out of 6 (half points possible) was given in each of the

three adjudication categories for each excerpt performance.

Pre-Test Questionnaire

The pre-test questionnaire was designed to provide background information regarding participant

on- and off-instrument warm-up practices and perceptions of the effects of warm-up on sound

quality (see Document, Supplemental Digital Content 2, pretest questionnaire,

http://links.lww.com/MSS/A564). Data regarding the location, type, duration, and severity of any

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participant physical symptoms was also obtained using a model developed by Ackermann,

Driscoll, and Kenny (3).

Fitness Self-Assessment

A validated fitness self-assessment VAS (34) (100mm scale) was used to assess participant

aerobic fitness and muscle strength; VAS data regarding participant flexibility, endurance, and

balance were also obtained.

Stratified Randomization (Figure 2)

Prior research has shown that pain (18), sex (15), and fitness levels (22) have the potential to

significantly impact muscle contraction amplitude and coordination. To control for these

variables, stratified randomization was used to allocate participants into warm-up groups. Sealed,

randomly ordered opaque envelopes containing warm-up group allocations were prepared by a

person not associated with the study for each of the 8 subject categories detailed in Figure 2.

Pain group determinations were based on responses to question 5 (presence of current physical

symptoms) in the pre-test questionnaire: a ‗yes‘ response placed participants in the ‗pain‘ group,

while a ‗no‘ response placed participants in the ‗no pain‘ group. Similarly, the average value of

participant responses to the aerobic fitness and muscular strength portions of the fitness self-

assessment VAS determined fitness group designations. An average value <50mm placed

participants in the ‗unfit‘ group, while an average value >50mm placed participants in the ‗fit‘

group.

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Violin Excerpts

A series of 5 musical excerpts [see Video, Supplemental Digital Content 3-7, recordings of

musical excerpts 1-5 (in corresponding order), 41-47 seconds, 8.6-9.8 MB,

http://links.lww.com/MSS/A565, http://links.lww.com/MSS/A566,

http://links.lww.com/MSS/A567, http://links.lww.com/MSS/A568,

http://links.lww.com/MSS/A569] were selected with the goal of eliciting performance of a range

of typical right arm bowing movements. Excerpt duration was kept brief (45-60 seconds each) to

avoid a warm-up effect from the first, pre-warm-up performances. A metronome (Tempo, iPhone

app, Frozen Ape Pte. Ltd.) was used during each excerpt performance to standardize

performance tempos. The performance order of excerpts was randomized for each participant,

and maintained for both pre and post warm-up performances.

Selected excerpts required the following movements:

1. Forceful right elbow flexion/extension over full range of motion [Fritz Kreisler, Praeludium

and Allegro, bars 1-22, crotchet = 108 beats per minute (bpm)]

2. Fast, alternating right shoulder abduction/adduction over full range of motion [Rodolphe

Kreutzer, Prelude #7 for Solo Violin, bars 9-26, crotchet = 108 bpm]

3. Moderate intensity right elbow flexion/extension over limited range of motion [Charles de

Beriot, Variations in d minor, Op. 1, bars 9-24, quaver = 92 bpm]

4. Sustained, rapid alternating right elbow flexion/extension and right wrist radial/ulnar

deviation over vey small range of motion [Joseph-Maurice Ravel, Sonata for Violin and

Piano, 1st mvt, rehearsal markings 9-11, quaver = 160 bpm]

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5. Slow, controlled right elbow flexion/extension over full range of motion [Johann Sebastian

Bach/Charles Gounod, Ave Maria, bars 5-15, crotchet = 60 bpm]

Ratings of Perceived Exertion

Ratings of perceived exertion (RPE), using the Borg scale from 6-20 (31), were obtained

following the completion of both the pre and post warm-up performances of excerpts.

Warm-up Protocols

All warm-ups were 15 minutes duration and designed to be moderate intensity activities, with

participants instructed to feel they were working ‗somewhat hard‘ (RPE=11-13).

Warm up protocols were:

Cardiovascular - brisk walk in the areas surrounding the test sites.

Musical – standard violin warm-up using specific exercises recommended by a

violin professor (see Document, Supplemental Digital Content 8, full description

of musical warm-up, http://links.lww.com/MSS/A570).

Core muscle - eight exercises designed to activate gluteal, abdominal, and

shoulder muscles in all 3 planes of movement. All movements were performed in

a slow, controlled fashion to ensure that core muscles were contracted for the

duration of the movement. Exercises could be modified to suit individual fitness

levels and were performed in the following sequence (see Table, Supplemental

Digital Content 9, full description of core muscle warm-up,

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http://links.lww.com/MSS/A571): Dual loading gluteal bridges; Single loading

gluteal bridge leg marches; Leg crossovers; Opposite arm/leg extension; Dynamic

side plank; Shoulder ―A‖; Shoulder ―T‖; Shoulder ―W‖.

Control - Participants sat quietly in a chair

Post-Test Questionnaire

The post-test questionnaire was dministered to gauge participant perceptions of the effect of the

assigned warm-up on performance and physical symptoms. See Document, Supplemental

Digital Content 10, post-test questionnaire, http://links.lww.com/MSS/A572.

Maximum Voluntary Contractions (MVC)

MVCs were performed after both the pre and post warm-up performances of the excerpts to

avoid any warm-up effects resulting from the MVC protocol. In all tests, participants were

instructed to isometrically contract the intended muscle(s) with maximum effort for 3 seconds

against a resistance provided by the same researcher for all participants. Each exercise was

repeated 3 times, separated by a 1-minute rest period. The following 13 tests were performed

(see Table, Supplemental Digital Content 11, detailed MVC descriptions,

http://links.lww.com/MSS/A573):

Standardized set of 5 shoulder exercises (17): resisted shoulder internal rotation at 90°

elbow flexion; resisted abduction at 90° abduction; resisted shoulder flexion at 125°

flexion; and resisted shoulder extension at 30° abduction

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http://links.lww.com/MSS/A573

http://links.lww.com/MSS/A571


Resisted elbow flexion and extension at 90° elbow flexion. Modifications of the protocols

of Khan et al. (21) and Staudenmann et al. (33)

Resisted wrist flexion and extension at 90° elbow flexion with forearm supported by

table. Adaptation of data from Weerakkody et al. (37)

Supine resisted abdominal crunch, supine resisted crossover crunch, and prone resisted

back extension. (14)

Signal Processing

Signal processing was performed in Matlab (Version 2014b, The Math Works, MA, USA). EMG

signals were high pass filtered at 10 Hz (zero lag, 8th Order Butterworth), rectified then the

linear envelope calculated by low pass filtering at 3 Hz (zero lag, 8th Order Butterworth). All

signals were visually inspected prior to processing by blinded study personnel; see Figure 3 for a

sample raw EMG signal. Using the maximum amplitude recorded for each muscle across all

MVC tests, the excerpt EMG signals were then normalized and expressed as %MVC.

Statistical Analysis

All statistical analyses were performed using Statistica 64 version 10 (StatSoft, Inc., Tulsa, OK).

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EMG Data

The EMG data was checked and confirmed to be normally distributed using probability plots.

Pre/post differences in the average EMG levels for different warm-up protocols, excerpts, fitness

groups, and pain groups were investigated for each muscle using a three-factor (warm-up

protocol X excerpt X pre/post) repeated-measures analysis of covariance (ANOVA). When

significant main or interaction effects were observed, a Tukey honestly significant difference

post hoc test was conducted to determine differences among the levels. A significance level

α=0.05 was set.

RPE

Differences in RPE were determined using Wilcoxon matched pairs tests to compare pre/post

RPE within each warm-up protocol. A significance level α=0.05 was set.

Sound Recording

Differences in perceived performance quality were determined using a two-factor (pre/post X

warm-up protocol) repeated-measures analysis of variance (ANOVA) for each of the three

adjudication scores (tone, intonation, overall performance) for each excerpt. When significant

main or interaction effects were observed, a Tukey honestly significant difference post hoc test

was conducted to determine specific significant differences. A significance level α=0.05 was set.

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Trial Registration

This study was prospectively registered with the Australian New Zealand Clinical Trials

Registry, ID: ACTRN12614000001695.

RESULTS

Muscle Activity: Mean activation Levels

Average muscle activity levels across ranged from 2.065 ± 0.98 %MVC (right posterior deltoid,

excerpt 5) to 55.41 ± 43.76 %MVC (right wrist flexors, excerpt 4). Significant differences in

muscle activity levels between excerpts were seen within each investigated muscle (F4,164 ≤ 3.08,

p≤0.02). See Figure 4.

Muscle Activity: Pre-Post Effects

Significant pre/post differences in muscle activity levels were only seen in the right upper

trapezius in the musical warm-up group (F3,45 = 4.00, p<0.02; pre: 6.9 ± 4.2 %MVC; post: 7.6 ±

4.1 %MVC) and right lower trapezius in the core muscle warm-up group (F3,44 = 2.99, p<0.05;

pre: 9.4 ± 6.3 %MVC; post: 8.7 ± 5.7 %MVC). No warm-up x pre/post interaction was observed

in any of the muscles investigated (F3,45 ≤ 2.18, p≥0.10).

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RPE

The RPE significantly decreased for all warm-up groups (Z≥1.99, p<0.05) except for the control

group (Z=1.18, p>0.23). See Figure 5.

Recording Adjudication

No significant differences were found in any adjudication scores for any of the groups (F3,45 ≤

5.43, p≥0.21). See Figure 6.

DISCUSSION

None of the investigated warm-ups significantly impacted musical performance quality or

muscle activity levels across all 16 investigated muscles. An acute increase in muscle activity

level occurred in the right upper trapezius in the musical warm-up group, and an isolated

decrease in muscle activity occurred in the lower trapezius in the core muscle warm-up group;

these outlying and contrasting results are likely anomalous. There was, however, a significant

decrease in RPE following all warm-up conditions in contrast to no change in RPE following 15

minutes of silent sitting (control condition).

The presence of significant differences in muscle activity levels between excerpts in all

investigated muscles, core and right arm musculature alike, confirms that the variable physical

demands of violin performance were successfully captured by the methodology of this

investigation. This face validity makes the absence of acute changes in muscle activity levels in

response to warm-up in even the most vigorous excerpt even more surprising. However, while

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these results run contrary to anecdotal evidence and pedagogical recommendations, these results

are consistent with the growing body of sports medical evidence suggesting that warm-up is only

an effective means of performance enhancement for strength and power outcomes (26). The

submaximal sustained muscle activity levels required by violin performance may not be acutely

affected by a 15-minute warm-up. Warm-ups of varying duration were not investigated and

could affect results, although, generally, warm-up durations longer than 10 minutes have not

been shown to have differential effects (9).

The absence of significant musical performance improvements following warm-up also runs

contrary to anecdotal evidence but is consistent with previous study (27). In this investigation, 46

of 55 (83.6%) participants anticipated that warm-up would improve performance quality on their

pre-test questionnaires, while outside listeners reported no significant improvements in

performance adjudication scores. A similar perceptual divide was also reported in a prior study

of vocal performance (27), suggesting that any benefits of warm-up for musical performance

may be imperceptible to all except the performers themselves. Relatedly, the absence of

significant differences between any first and second excerpt performances (e.g. training effect)

demonstrates that repetition-based improvements were also imperceptible to trained listeners.

This indicates either that a more sensitive measurement tool is necessary to capture performance

improvements resulting from warm-up and/or repetition, or that acute performance

improvements from both warm-up and repetition in expert violinists are in fact imperceptible

even to trained listeners.

An important finding in this investigation is the fact that participants subjectively reported that

all 3 warm-ups significantly decreased performance exertion, in spite of objective muscle

activity data to the contrary. The absence of a significant decrease in exertion in the control

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condition indicates that any warm-up induced decreases in exertion were not the result of further

familiarization with the musical excerpts. Further, the decrease in exertion across all 3 warm-up

protocols, rather than the musical protocol only, suggests that warm-up benefits on exertion are

not simply the result of increased time with the instrument prior to the second excerpt

performance. The observed warm-up benefits appear to be the result of other phenomena.

One possible physiological explanation for the decrease in exertion following warm-up is an

increased efficiency of oxygen delivery. Prior research demonstrates that muscle temperature

rises from resting levels after 3-5 minutes of activity, reaching equilibrium after 10-20 minutes

of continued activity (30). Associated with this muscle temperature increase is a decreased 2

response time (11), regardless of the intensity of prior warm-up activity (19), due to a decrease in

hemoglobin O2 affinity (5), increase in myoglobin O2 affinity (5, 29), and increase in total blood

flow via vasodilation (4). Whether these physiological changes impact performance of

submaximal, repetitive activities has yet to be investigated. Each of the 15-minute, moderate

intensity warm-up protocols in this investigation may have sufficiently affected such

physiological variables to create the observed significant drop in RPE.

An additional, more sparingly investigated hypothesis for participants‘ decreased post-warm-up

exertion is that warm-up is psychologically beneficial, as it provides time for valuable mental

preparation before, in this case, the second performance of the excerpts (8). If this were the case,

however, the control condition should have also resulted in decreased exertion, as 15 minutes of

silent sitting affords the same mental preparation time as the three experimental warm-up

protocols. Further, prior research has shown, albeit in athletics rather than performing arts, that

any positive psychological responses to the completion of a warm-up (e.g. maintenance of pre-

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performance habits) have an insignificant impact on performance (25). As such, it seems

unlikely that warm-up benefits are the result of these psychological effects.

A final, related hypothesis for the decrease in post-warm-up exertion in the warm-up groups but

not the control group is that warm-up has a placebo effect. A large majority of participants

(51/55, 92.7%) reported that warm-up was a regular part of their pre-practice and performance

routines, signifying that most viewed warm-up as a beneficial preparatory activity. Accordingly,

the perceived exertion results in the warm-up and control groups could be an extension of

previously held attitudes. Conversely, other physiological or psychological factors not

considered in this manuscript could also be responsible for these perceived warm-up benefits;

further research is necessary.

In summary, this investigation provides some insight into acute warm-up benefits (decreased

exertion) that have led to the widespread adoption of this practice for submaximal activities such

as musical performance, and also provides data that refutes potential hypotheses regarding the

physiological mechanisms behind warm-up benefits in violin performance. Limitations of this

study were that sEMG amplitude was the only investigated physiological outcome, a possible

placebo effect of warm-up attitudes was not controlled, and the performance quality

measurement protocol was potentially not sensitive enough to detect small changes in

performance quality. ascular and 2 responses to warm-up, as well as the warm-up placebo

effect, appear to be potentially fruitful avenues for future investigation of warm-up benefits.

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CONCLUSION

Cardiovascular, core muscle, and musical warm-up had no acute impact on muscle activity levels

or performance quality. RPE was significantly decreased across all 3 warm-up conditions but not

the control condition. This investigation provides data from the performing arts in support of the

growing body of sports medical evidence suggesting that warm-up only effectively enhances

maximal strength and power performance. Future investigation should focus on elucidating the

mechanisms behind subjective warm-up benefits during submaximal activity.

ACKNOWLEDGEMENTS

This work was supported by the Australian-American Fulbright Commission and an Australian

Research Council Linkage Project Grant (LP0989486).

CONFLICT OF INTEREST

The authors declare no conflicts of interest. The results of this study do not constitute an

endorsement by the American College of Sports Medicine.

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REFERENCES

1. Abreu Ramos AM, Micheo WF. Lifetime prevalence of upper-body musculoskeletal

problems in a professional-level symphony orchestra. Medical Problems of Performing

Artists. 2007;22(3):97-104.

2. Ackermann B, Adams R, Marshall E. The effect of scapula taping on electromyographic

activity and musical performance in professional violinists. Australian Journal of

Physiotherapy. 2002;48(3):197-203.

3. Ackermann B, Driscoll T, Kenny DT. Musculoskeletal pain and injury in professional

orchestral musicians in Australia. Medical Problems of Performing Artists.

2012;27(4):181-7.

4. Barcroft H, Edholm O. The effect of temperature on blood flow and deep temperature in

the human forearm. The Journal of Physiology. 1943;102(1):5-20.

5. Barcroft J, King W. The effect of temperature on the dissociation curve of blood. The

Journal of Physiology. 1909;39(5):374-84.

6. Behm DG, Chaouachi A. A review of the acute effects of static and dynamic stretching

on performance. European Journal of Applied Physiology. 2011;111(11):2633-51.

7. Bejjani FJ, Kaye GM, Benham M. Musculoskeletal and neuromuscular conditions of

instrumental musicians. Archives of Physical Medicine and Rehabilitation.

1996;77(4):406-13.

8. Bishop D. Warm up I. Sports Medicine. 2003;33(6):439-54.

9. Bishop D. Warm up II. Sports Medicine. 2003;33(7):483-98.

10. Brukner P, Khan K, Bahr R. Principles of injury prevention. In: P Brukner, K Khan

editors. Brukner & Khan's Clinical Sports Medicine. Sydney: McGraw-Hill; 2012, p 81.

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11. Burnley M, Jones AM, Carter H, Doust JH. Effects of prior heavy exercise on phase II

pulmonary oxygen uptake kinetics during heavy exercise. Journal of Applied Physiology.

2000;89(4):1387-96.

12. Cohen J. Statistical Power Analysis for the Behavioral Sciences. 2nd ed. Hillsdale, NJ:

Erlbaum; 1988.

13. Criswell E. Cram's introduction to surface electromyography. Jones & Bartlett

Publishers; 2010.

14. Dankaerts W, ‘Sullivan PB, Burnett AF, Straker LM, Danneels LA. Reliability of EMG

measurements for trunk muscles during maximal and sub-maximal voluntary isometric

contractions in healthy controls and CLBP patients. Journal of Electromyography and

Kinesiology. 2004;14(3):333-42.

15. DeMont R, Lephart S. Effect of sex on preactivation of the gastrocnemius and hamstring

muscles. British Journal of Sports Medicine. 2004;38(2):120-4.

16. Faul F, Erdfelder E, Lang A-G, Buchner A. G* Power 3: A flexible statistical power

analysis program for the social, behavioral, and biomedical sciences. Behavior Research

Methods. 2007;39(2):175-91.

17. Ginn K, Halaki M, Cathers I. Revision of the Shoulder Normalization Tests is required to

include rhomboid major and teres major. Journal of Orthopaedic Research.

2011;29(12):1846-9.

18. Graven-Nielsen T, Svensson P, Arendt-Nielsen L. Effects of experimental muscle pain on

muscle activity and co-ordination during static and dynamic motor function.

Electroencephalography and Clinical Neurophysiology/Electromyography and Motor

Control. 1997;105(2):156-64.

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19. Hajoglou A, Foster C, de Koning JJ, Lucia A, Kernozek TW, Porcari JP. Effect of warm-

up on cycle time trial performance. Medicine and Science in Sports and Exercise.

2005;37(9):1608-14.

20. Iñesta C, Terrados N, García D, Pérez JA. Heart rate in professional musicians. Journal

of Occupational Medicine and Toxicology. 2008;3:16.

21. Khan SI, McNeil CJ, Gandevia SC, Taylor JL. Effect of experimental muscle pain on

maximal voluntary activation of human biceps brachii muscle. Journal of Applied

Physiology. 2011;111(3):743-50.

22. Laforest S, St-Pierre DM, Cyr J, Gayton D. Effects of age and regular exercise on muscle

strength and endurance. European Journal of Applied Physiology and Occupational

Physiology. 1990;60(2):104-11.

23. Leetun DT, Ireland ML, Willson JD, Ballantyne BT, Davis IM. Core stability measures

as risk factors for lower extremity injury in athletes. Medicine and Science in Sports and

Exercise. 2004;36(6):926-34.

24. Markison R. Adjustment of the musical interface. In: C Wynn Parry, I Winspur editors.

The Musician's Hand: A Clinical Guide. London: Martin Dunitz; 1998, p 158.

25. Massey BH, Johnson WR, Kramer GF. Effect of warm-up exercise upon muscular

performance using hypnosis to control the psychological variable. Research Quarterly.

American Association for Health, Physical Education and Recreation. 1961;32(1):63-71.

26. McCrary JM, Ackermann BJ, Halaki M. A systematic review of the effects of upper body

warm-up on performance and injury. British Journal of Sports Medicine. 2015:bjsports-

2014-094228.

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27. Moorcroft L, Kenny DT. Singer and listener perception of vocal warm-up. Journal of

Voice. 2013;27(2):e1-e13.

28. Press J, Levy AE. Electromyographic analysis of muscular activity in the upper extremity

generated by supporting a violin with and without a shoulder rest. Medical Problems of

Performing Artists. 1992;7:103-9.

29. Richardson R, Noyszewski E, Kendrick K, Leigh J, Wagner P. Myoglobin O2

desaturation during exercise. Evidence of limited O2 transport. Journal of Clinical

Investigation. 1995;96(4):1916.

30. Saltin B, Gagge At, Stolwijk J. Muscle temperature during submaximal exercise in man.

Journal of Applied Physiology. 1968;25(6):679-88.

31. SENIAM [Internet]. Nijmegen, The Netherlands: SENIAM. Available from: seniam.org.

32. Shan G, Visentin P, Schultz A. Multidimensional signal analysis as a means of better

understanding factors associated with repetitive use in violin performance. Medical

Problems of Performing Artists. 2004;19(3):129-39.

33. Staudenmann D, van Dieën JH, Stegeman DF, Enoka RM. Increase in heterogeneity of

biceps brachii activation during isometric submaximal fatiguing contractions: a

multichannel surface EMG study. Journal of Neurophysiology. 2014;111(5):984-90.

34. Strøyer J, Essendrop M, Jensen LD, Warming S, Avlund K, Schibye B. Validity and

reliability of self-assessed physical fitness using visual analogue scales. Perceptual and

Motor Skills. 2007;104(2):519-33.

35. Trost SG, Owen N, Bauman AE, Sallis JF, Brown W. Correlates of adults' participation

in physical activity: review and update. Medicine and Science in Sports and Exercise.

2002;34(12):1996-2001.

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36. Wallmann HW, Mercer JA, McWhorter JW. Surface electromyographic assessment of

the effect of static stretching of the gastrocnemius on vertical jump performance. The

Journal of Strength & Conditioning Research. 2005;19(3):684-8.

37. Weerakkody N, Percival P, Morgan D, Gregory J, Proske U. Matching different levels of

isometric torque in elbow flexor muscles after eccentric exercise. Experimental Brain

Research. 2003;149(2):141-50.

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FIGURE CAPTIONS

Figure 1: Testing protocol flow diagram

Figure 2: Stratified randomization flow diagram

Figure 3: A sample raw EMG for a typical subject pre (black) and post (grey) warm-up in the

musical warm-up group for right/left upper trapezius (U Trap), right/left erector spinae (T ES),

right/left upper abdominals (U Abdom), right/left lower abdominals (L Abdom), right pectoralis

major (Pec), right anterior deltoid (A Delt), right posterior deltoid (P Delt), right lower trapezius

(L Trap), right biceps brachii (Bi Br), right middle triceps brachii (M Tri), right wrist flexors

(Flexors), right wrist extensors (Extensors). The vertical lines indicate the vertical scales

equivalent to 50 mV. The pre and post signals are offset from each other for clarity.

Figure 4: Mean (±SD) muscle activity levels by excerpt

Lower case letters correspond to the following significant differences in muscle activity levels

between excerpts: a = 1 vs 2; b = 1 vs 3; c = 1 vs 4; d = 1 vs 5; e = 2 vs 3; f = 2 vs 4; g = 2 vs 5;

h = 3 vs 4; i = 3 vs 5; j = 4 vs 5

Figure 5: Rating of perceived exertion (RPE), pre and post warm-up for each group.

* significant pre/post difference (p<0.05)

Figure 6: Musical performance adjudication scores for each group, pre and post warm-up for

each excerpt

* significant pre/post difference (p<0.05)

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SUPPLEMENTAL DIGITAL CONTENT

Supplemental Digital Content 1.docx, Document, full violin performance adjudication rubric

Supplemental Digital Content 2.docx, Document, pre-test questionnaire

Supplemental Digital Content 3.m4v, Video, recording of musical excerpt 1





Supplemental Digital Content 8.docx, Document, full description of musical warm-up

Supplemental Digital Content 9.docx, Table, full description of core muscle warm-up

Supplemental Digital Content 10.docx, post-test questionnaire

Supplemental Digital Content 11.docx, Table, full description of maximum voluntary contraction

protocol

ACCEPTED


Figure 1

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Figure 2

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Figure 3

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Figure 4

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Figure 5

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Figure 6

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Supplemental Digital Content 1

Effects of warm ups adjudication sheet

N.B.

- each performance is ranked on its own individual merits and not in comparison to other

performances prior or following.

- A field for comment has been left should the adjudicator would like to make a comment

- Decimal points may be used if required

Grade descriptors:

6: An extraordinary performance

5: An outstanding performance – a performance which may have contained a minor blemish

4: An excellent performance – a performance that may have contained a few minor blemishes

3: A competent performance – a performance that shows occasional lapses

2: An insecure performance – a performance showing frequent lapses

1: Unsuccessful attempt – a performance of generally unacceptable quality

Performance

Reference

Intonation

accuracy

(1-6)

Tone Clarity

(1-6)

Overall

Impression

(1-6)

Comment

ACCEPTED



Pre-test Questionnaire

Please check only one response per question unless instructed otherwise.

1. Do you warm-up ON YOUR INSTRUMENT :

a. Before PERFORMING or REHEARSING?

Yes

No

Occasionally

b. Before PRACTISING?

Yes

No

Occasionally

2. Do you warm up AWAY FROM YOUR INSTRUMENT :

a. Before PERFORMING or REHEARSING?

Yes

No

Occasionally

b. Before PRACTISING?

Yes

No

Occasionally

c. What does this warm-up involve? ________________________________________

3. If you warm-up, what factors influence your decision to do this? (check all that apply)

Advice from teacher

Advice from health professional

Advice from friends

Positive personal experiences with warm-up

Other (please describe) _____________________________________________

4. How do you think warm-up will affect your sound quality?

Improve sound quality

No effect

Degrade sound quality

5. Are you currently experiencing any physical symptoms, such as aches, pain, weakness, lack of

control, numbness or tingling?

Yes

ACCEPTED


No

Note: if you answered “no” to question 5, your questionnaire ends here! If you answered “yes” to

question 5, continue to the 2nd page.

6. Please indicate the location(s) of your current physical symptoms (PS) on the body chart below.

Shade an area and label the first PS as A, the second as B, etc. (see provided example)

Ackermann,

2012

For each shaded area above, please complete details below on the PS. Please also rate the severity of the

PS out of 10, where 0 is no pain and 10 is the worst pain you can imagine. If the PS varies, please

indicate the lowest to highest pain ratings.

PS (letter) Duration

(weeks)

Affecting

playing?

(Y/N)

Type of PS (from list

below)

Intermittent

or constant?

Severity

(/10)

Type of PS: Aching, sharp, burning, throbbing, cramping, pulling, tingling, hot, numb, cold, shooting,

heavy, tender, weak, loss of control, tiring, other (specify)

ACCEPTED



15 Minute Violin Warm-Up routine

It is possible to change the order of these exercises.

1. Right Arm Exercise (1 minute)

Play the note ‘D’ on A-string using whole bows. Play 4 whole bows at 5 different sound points on the

string: (near the fingerboard->between middle and fingerboard-> at the middle-> between middle and

bridge-> next to the bridge). Focus on having free, smooth motion of the right arm, lots of echo in the

tone, and a wide oscillation of the string.

2. Left Hand Exercise (1 minute)

Set all the fingers in 1st position on A-string to the notes B-C#-D-E, Metronome Speed: Crotchet=80. Lift

each finger starting with 4th finger (i.e. E-D, then D-C#, then C#-B, then B-A) Repeat each combination

two times playing crotchets and four times in quavers. Focus on having a quick lift of fingers and a loose

feel of the hand when the fingers are in the air.

After reaching open A-string, work dropping the fingers down (i.e. A-B, then B-C#, then C#-D, then D-E).

Repeat each combination two times playing crotchets and four times playing quavers. Focus on having a

quick drop of fingers on the string and a loose feel of the hand when the fingers are on the string.

3. Right Arm Exercise 2 – Weight Exercise (30 Seconds)

Using whole bows alternate between heavy and light bow feel (i.e. on a down bow stroke play bottom

half of the bow heavy and forte, and the top half light and piano; on an up bow again start heavy and

forte, and in the lower half play light and piano). Then do two heavy-light cycles per bow stroke on a

down-bow and on an up-bow (i.e. heavy-light-heavy-light), then 3, 4, 6 and 8 heavy-light cycles in a bow

stroke.

ACCEPTED


4. Left Arm Exercise 2 – Henry Schradieck Op. 1 Part 1. (1 minute)

Using Metronome Speed Crotchet =80 play through Part A Exercises 1-8.

5. Right Arm Exercise 3 – Speed Exercise (30 Seconds)

This exercise is identical to the Weight Exercise with the difference that instead of heavy-light pattern

the fast-slow pattern will be used.

Using whole bows alternate between fast and slow bow speed (i.e. on a down bow stroke play bottom

half of the bow fast and forte, and the top half slow and piano; on an up bow again start fast and forte,

and in the lower half play slow and piano). Then do two fast-slow cycles per bow stroke on a down-bow

and on an up-bow (i.e. fast-slow-fast-slow), then 3, 4, 6 and 8 fast-slow cycles in a bow stroke.

ACCEPTED


6. Left Arm Exercise 3 – Vibrato (2 minutes)

Place your hand in 3rd or 4th position in such a way that your wrist is touching lightly the side of the

violin. Place the fingers down on the string (one at a time) and move the hand from the wrist in such a

way that the nail joint of each finger opens and closes and the finger on the string rolls from the tip to

the pad and back to the tip. Start slow and build up the speed to full vibrato.

7. Right Arm Exercise 4 – String Crossings Rodolphe Kreutzer Etude No. 7 Excerpt (1

minute)

Start slowly focusing on the precise movement of the upper arm and elbow moving to the correct string.

Then increase the speed.

ACCEPTED


8 Right Arm Exercise 5 – String Crossings Rodolphe Kreutzer Etude No. 13 Excerpt (1

minute)

Play in the top half of the bow focusing on the coordination and smooth movement of the elbow, wrist

and fingers for string crossings.

9. Left Arm Exercise 4 – Shifting (1 minute)

ACCEPTED


10 Scale (5 minutes)

Play 3 octave G major scale at a speed M=50 in Slurs of 3 at three notes to a beat; then in slurs of 8 at

eight notes to a beat; and then sautille at the same speed (optionally it is possible to play each note

repeated twice in sautille stroke).

11 Arpeggios (1 minute)

Play 3 octave G major and minor triads in slurs of 3 and 6

ACCEPTED


Exercise Description Modification Diagram

Dual loading gluteal bridges

Participants lay on their back with knees bent, both feet flat on the ground, and arms resting beside the torso. Driving through the heels and contracting the gluteals, hips were lifted off the ground to form a straight line between the knees, hips, and torso. The participant paused in this position before slowly returning the hips back to the ground. Movement was repeated for a total of 10 repetitions.

Decreased intensity—participants contracted gluteals and lifted their body weight off the pelvis before returning to the ground. Formation of a straight line between the knees, hips, and torso was not required.

Single loading gluteal bridge leg marches

Participants lay on their back with knees bent and both feet flat on the ground. Hips were lifted off the ground to form a straight line between their knees, hips and torso. From this position, one foot was lifted off the ground, bringing the thigh perpendicular to the ground and keeping the hips high. The raised foot was then returned to the starting position and the same movement was performed with the opposite leg without dropping the hips. This sequence was repeated for a total of 20 total repetitions, 10 on each leg.

Decreased intensity—participants contracted gluteals to lift body weight off the pelvis. From this position, one leg was extended until straight and then returned to the starting position. Movement was replicated with the opposite leg.

Leg crossovers Participants lay on their back, extended both arms perpendicularly to the torso, and extended the legs vertically. Without lifting the scapulae off the ground, legs were rotated as far as possible to one side of the torso before being returned to the starting position. This movement was then repeated in the opposite direction. A total of 20 repetitions were performed, 10 in each direction.

Decreased intensity—participants performed the same movement with knees flexed to 90-degrees.

Modified

Modified

Modified


ACCEPTED


Opposite arm/leg extension

Participants began on hands and knees with a flat back. From this position, participants extended an arm and leg on opposite sides of the body (e.g. left arm, right leg) until straight, keeping the torso steady. The arm and leg were then returned to the starting position. A total of 20 repetitions were performed, 10 on each side.

Decreased intensity—participants were instructed to decrease the range of motion if lower intensity movement was required.

Dynamic side plank

Participants began lying on their side with the trunk propped up on their forearm. Participants then contracted their oblique muscles to form a straight line between the feet, hips, and torso. The hips were then dropped back down towards the ground in a slow and controlled fashion. After briefly touching the hip back to the floor, the movement was repeated. A total of 20 repetitions were performed, 10 on each side.

Decreased intensity—participants lifted their hips off the ground such that a straight line was formed between the knees, hips, and torso. Feet remained rested on the ground throughout the duration of the activity

Shoulder ‘A’ Participants began standing, with feet shoulder width apart, knees slightly bent, and arms by the sides. In a slow, controlled manner, arms were raised directly in front of the torso, finishing fully extended on both sides of the head. Arms were then slowly lowered back to the starting position, with a focus on maintaining contraction of the trapezius and anterior deltoid muscles throughout the descent. A total of 10 repetitions were performed.

No modifications of this exercise were necessary.

Modified

ACCEPTED


Shoulder ‘T’ Participants began with knees flexed to approximately 45-degrees and the torso leaning over the toes, parallel to the ground. Participants were instructed to extend their arms toward the ground with palms facing each other, and then retract the scapulae and lift the arms to bring the arms parallel to the ground and fully extended out from the torso. The arms were then slowly returned to the starting position. A total of 10 repetitions were performed.


Shoulder ‘W’ Participants began with knees flexed to approximately 45-degrees and the torso leaning over the toes, parallel to the ground. With elbows flexed 90-degrees and the palms facing away from the thighs, participants externally rotated the humerus until the hands were parallel with the torso. The hands were then returned to the starting position in a slow, controlled manner. Care was taken to ensure that the elbows remained near the torso throughout the movement. A total of 10 repetitions were performed.


ACCEPTED



Post-test Questionnaire

1. Circle your average exertion during the previous trial on the scale below.

2. If you had physical symptoms at the beginning of testing, how did the warm-up affect these symptoms?

a. Symptom A Improved symptoms No effect on symptoms Exacerbated symptoms

b. Symptom B Improved symptoms No effect on symptoms Exacerbated symptoms

ACCEPTED


c. Symptom C Improved symptoms No effect on symptoms Exacerbated symptoms

3. Rate the overall effect of the warm-up compared to your expectations. More negative effect than expected Same effect as expected More positive effect than expected

ACCEPTED


Exercise (arm) Description of movement Diagram (arrows point direction of applied force)

Empty can (R/L) Participant sat in erect posture with no back support. Shoulder abducted 90° with elbow extended and internal humeral rotation; arm abducted as resistance applied at wrist.

Flexion 125

° (R/L) Participant sat in erect posture with no back support. Shoulder flexed at 125°. Shoulder flexed as resistance applied above the elbow and at the inferior angle of the scapula to de-rotate scapula.

Internal rotation 90° (R/L)

Participant sat in erect posture with no back support. Shoulder abducted 90° in plane of scapula with elbow flexed 90° and neutral humeral rotation. Arm internally rotated as resistance applied to wrist.


ACCEPTED


Shoulder extension (R/L)

Participant sat in erect posture with no back support. Shoulder abducted 30°, elbow fully extended. Shoulder extended as resistance applied at wrist.

Palm press Participant sat in erect posture with no back support. Shoulders bilaterally flexed 90° with heel of hands together, elbows flexed 20°, and arms horizontally adducting.

Elbow flexion (R) Participants sat in erect posture with no back support. Right elbow flexed 90° and right forearm supinated such that the right palm was parallel to the ceiling. Elbow flexed as resistance applied at palm towards floor.

ACCEPTED


Elbow extension (R) Participants assumed same starting position as elbow flexion MVC. Elbow extended as resistance applied at palm towards ceiling.

Wrist flexion (R) Participants placed right forearm on a table, palm facing the ceiling, with the edge of the table in line with the wrist; padding under the forearm was provided when requested. Wrist flexed as resistance applied to palm towards floor.

Wrist extension (R) Participants placed right forearm on a table, palm facing the floor, with the edge of the table in line with the wrist; padding under the forearm was provided when requested. Wrist extended as resistance applied to back of hand towards floor.

ACCEPTED


Crunch Participants lay on their back with feet flat on the floor and arms crossed across the chest. Torso flexed such that shoulder blades were ~20cm off the ground as resistance applied bilaterally to upper chest.

Crossover crunch (R/L)

Participants lay on their back with feet flat on the floor and arms crossed across the chest. Torso rotated to bring 1 shoulder ~30 off the ground as counter-rotary force applied to the lifted shoulder.

Back extension Participants lay prone on their torso, with both hands resting lightly on the back of the head. Back was extended such that lifted the chest ~20cm off the ground as force was applied bilaterally to scapulae.

ACCEPTED

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Acute Warm-up Effects in Submaximal Athletes

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