%0 Journal Article
%~ PubMed
%A Reed, Darren
%A Cathers, Ian
%A Halaki, Mark
%A Ginn, Karen
%T Does supraspinatus initiate shoulder abduction?
%B Journal of Electromyography & Kinesiology
%D 2013
%C United Kingdom
%I Elsevier Ltd.
%V 23
%N 2
%P 425-429
%@ 1873-5711
%X 
%Z FOR Codes: 110603 110317


%0 Journal Article
%~ PubMed
%A Tardo, Daniel T
%A Halaki, Mark
%A Cathers, Ian
%A Ginn, Karen A
%T Rotator cuff muscles perform different functional roles during shoulder external rotation exercises.
%B Clinical Anatomy
%D 2013
%C United States
%I John Wiley & Sons, Inc.
%V 26
%N 2
%P 236-243
%@ 1098-2353
%X The aim of this study was to compare activity in shoulder muscles during an external rotation task under conditions of increasing arm support to investigate whether changing support requirements would influence muscle recruitment levels, particularly in the rotator cuff (RC) muscles. Electromyographic recordings were collected from seven shoulder muscles using surface and indwelling electrodes. The dominant shoulder of 14 healthy participants were examined during dynamic shoulder external rotation performed at 90?? abduction with the arm fully supported, partially supported, and unsupported. Linear regressions between arm support load and the averaged muscle activity across participants for each muscle showed infraspinatus predominantly contributing to rotating the shoulder whilst supraspinatus, deltoid, upper trapezius, and serratus anterior were predominantly functioning in support/stabilization roles. During dynamic shoulder external rotation in mid-range abduction, the RC muscles perform different functional roles. Infraspinatus is responsible for producing external rotation torque, supraspinatus is playing a larger joint stabilizer role, and subscapularis is contributing minimally to joint stability. The results also indicate that increasing support load requirements during an external rotation task may be a functionally specific way to retrain the stabilization function of axioscapular muscles. Manipulating joint stabilization requirements while maintaining constant rotational load is a novel method of investigating the differential contribution of muscles to joint movement and stabilization during a given task. Clin. Anat. 2012. ?? 2012 Wiley Periodicals, Inc.
%Z FOR Codes: 110999 110603


%0 Book Section
%A Halaki, Mark
%A Ginn, Karen
%T Normalization of EMG Signals: To Normalize or Not to Normalize and What to Normalize to?
%B Computational Intelligence in Electromyography Analysis- A Perspective on Current Applications and Future Challenges
%D 2012
%C Croatia
%I InTech
%V 
%N 
%P 175-194
%@ 9789535108054
%X 
%Z FOR Codes: 80199


%0 Journal Article
%~ PubMed
%A Wattanaprakornkul, Duangjai
%A Halaki, Mark
%A Boettcher, Craig
%A Cathers, Ian
%A Ginn, Karen A
%T A comprehensive analysis of muscle recruitment patterns during shoulder flexion: An electromyographic study.
%B Clinical Anatomy
%D 2011
%C United States
%I John Wiley & Sons, Inc.
%V 24
%N 5
%P 619-626
%@ 1098-2353
%X Although flexion is a common component of the routine clinical assessment of the shoulder the muscle recruitment patterns during this movement are not clearly understood making valid interpretation of potential muscle dysfunction problematic. The purpose of this study was to comprehensively examine shoulder muscle activity during flexion in order to compare the activity levels and recruitment patterns of shoulder flexor, scapular lateral rotator and rotator cuff muscles. Electromyographic (EMG) data were recorded from 12 shoulder muscles sites in 15 volunteers. Flexion was performed in standing in the sagittal plane at no load, 20%, and 60% of each subject''s maximum load. EMG data were normalized to maximum values obtained during maximum voluntary contractions. Results indicated that anterior deltoid, pectoralis major, supraspinatus, infraspinatus, serratus anterior, upper, and lower trapezius were activated at similar moderate levels. However, subscapularis was activated at low levels and significantly lower than supraspinatus and infraspinatus. Similar activity patterns across time were demonstrated in the muscles that produce flexion torque, laterally rotate the scapula, as well as supraspinatus and infraspinatus, and did not change as flexion load increased. The onset of activity in supraspinatus and anterior deltoid occurred at the same time and prior to movement of the limb at all loads with infraspinatus activity also occurring prior to movement onset at the medium and high load conditions only. Posterior rotator cuff muscles appear to be counterbalancing anterior translational forces produced during flexion and it would appear that supraspinatus is one of the muscles that consistently "initiates" flexion. Clin. Anat. 24:619-626, 2011. ?? 2011 Wiley-Liss, Inc.
%Z FOR Codes: 110699 110603 110999


%0 Journal Article
%~ PubMed
%A Wattanaprakornkul, Duangjai
%A Halaki, Mark
%A Cathers, Ian
%A Ginn, Karen A
%T Direction-specific recruitment of rotator cuff muscles during bench press and row.
%B Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology
%D 2011
%C United Kingdom
%I Elsevier Ltd
%V 21
%N 6
%P 1041-9
%@ 1873-5711
%X Recent studies indicate that rotator cuff (RC) muscles are recruited in a reciprocal, direction-specific pattern during shoulder flexion and extension exercises. The main purpose of this study was to determine if similar reciprocal RC recruitment occurs during bench press (flexion-like) and row (extension-like) exercises. In addition, shoulder muscle activity was comprehensively compared between bench press and flexion; row and extension; and bench press and row exercises. Electromyographic (EMG) activity was recorded from 9 shoulder muscles sites in 15 normal volunteers. All exercises were performed at 20, 50 and 70% of subjects'' maximal load. EMG data were normalized to standard maximal voluntary contractions. Infraspinatus activity was significantly higher than subscapularis during bench press, with the converse pattern during the row exercise. Significant differences in activity levels were found in pectoralis major, deltoid and trapezius between the bench press and flexion exercises and in lower trapezius between the row and extension exercises. During bench press and row exercises, the recruitment pattern in each active muscle did not vary with load. During bench press and row exercises, RC muscles contract in a reciprocal direction-specific manner in their role as shoulder joint dynamic stabilizers to counterbalance antero-posterior translation forces.
%Z FOR Codes: 110601 110603


%0 Journal Article
%~ PubMed
%A Yiasemides, Ross
%A Halaki, Mark
%A Cathers, Ian
%A Ginn, Karen A
%T Does passive mobilization of shoulder region joints provide additional benefit over advice and exercise alone for people who have shoulder pain and minimal movement restriction? A randomized controlled trial.
%B Physical Therapy
%D 2011
%C United States
%I American Physical Therapy Association
%V 91
%N 2
%P 178-189
%@ 1538-6724
%X Passive mobilization of shoulder region joints, often in conjunction with other treatment modalities, is used for the treatment of people with shoulder pain and minimal movement restriction. However, there is only limited evidence supporting the efficacy of this treatment modality.
%Z FOR Codes: 110317


%0 Journal Article
%~ PubMed
%A Ginn, K A
%A Halaki, M
%A Cathers, I
%T Revision of the Shoulder Normalization tests is required to include rhomboid major and teres major.
%B Journal of orthopaedic research : official publication of the Orthopaedic Research Society
%D 2011
%C United States
%I John Wiley & Sons, Inc.
%V 29
%N 12
%P 1846-9
%@ 1554-527X
%X The four "Shoulder Normalization Tests" were found previously to be a parsimonious set of isometric tests that produce maximal voluntary isometric contractions (MVIC) in the supraspinatus, infraspinatus, subscapularis, trapezius, serratus anterior, deltoid, latissimus dorsi, and pectoralis major [Boettcher et al. (2008). J Orthop Res 26:1591-1597]. However, these tests have not been validated for rhomboid major and teres major. In the current study, these Shoulder Normalization Tests were evaluated and compared to three other tests that could possibly elicit maximum activity in rhomboid major and teres major: abduction/extension in 90?? abduction; adduction at 90?? abduction; and extension in 30?? abduction. No statistical difference was found in the mean activation of rhomboid major and teres major in these additional MVIC tests compared to the Shoulder Normalization Tests. However, the extension MVIC test produced maxima for at least 50% of subjects in rhomboid major, teres major, and latissimus dorsi. We concluded that the original Shoulder Normalization Tests should be expanded to include the extension MVIC test. The EMG normalization reference value for any of the above muscles would be the maximum EMG level generated across these Revised Shoulder Normalization Tests.
%Z FOR Codes: 110603 110999


%0 Journal Article
%~ PubMed
%A Wattanaprakornkul, Duangjai
%A Cathers, Ian
%A Halaki, Mark
%A Ginn, Karen A
%T The rotator cuff muscles have a direction specific recruitment pattern during shoulder flexion and extension exercises.
%B Journal of science and medicine in sport / Sports Medicine Australia
%D 2011
%C Australia
%I Elsevier Australia
%V 14
%N 5
%P 376-82
%@ 1878-1861
%X A recent study has shown that posterior rotator cuff (RC) muscles are recruited at significantly higher levels than the anterior RC during shoulder flexion. It was proposed that the mechanism whereby the posterior RC muscles were providing shoulder stability during flexion was to counterbalance potential anterior humeral head translation caused by flexion torque producing muscles. This hypothesis implies that anterior RC activity should be higher than posterior RC activity during extension to prevent posterior humeral head translation. As the normal recruitment pattern of the RC during extension has not been established, the purpose of this study was to examine this hypothesis by comparing shoulder muscle activation levels and recruitment patterns during flexion and extension exercises. Electromyographic (EMG) activity was recorded from 9 shoulder muscles in 15 volunteers. Flexion and extension exercises were performed in prone at 20%, 50%, and 70% of each participant''s maximal load. A repeated measures ANOVA was used to determine differences between exercises, muscles and loads, while Pearson''s correlation analysis was used to relate mean EMG patterns. During extension subscapularis and latissimus dorsi were activated at higher levels than during flexion; during flexion, supraspinatus, infraspinatus, deltoid, trapezius, and serratus anterior were more highly activated than during extension. In addition, the pattern of activity in each muscle did not vary with load. These results support the hypothesis that during flexion and extension the RC muscles are recruited in a direction specific manner to prevent potential antero-posterior humeral head translation caused by torque producing muscles.
%Z FOR Codes: 110604 110317


%0 Journal Article
%~ PubMed
%A Johnson, Victoria L
%A Halaki, Mark
%A Ginn, Karen A
%T The use of surface electrodes to record infraspinatus activity is not valid at low infraspinatus activation levels.
%B Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology
%D 2011
%C United Kingdom
%I Elsevier Ltd
%V 21
%N 1
%P 112-8
%@ 1873-5711
%X Limited information is available to support the validity of using surface electrodes to record activity from infraspinatus. The aims of this study were to compare infraspinatus activity recorded using surface and intramuscular electrodes during several shoulder isometric and dynamic tasks and to establish if infraspinatus activity recorded using intramuscular electrodes is representative of whole muscle activity. Surface and intramuscular electrodes were placed over infraspinatus in nine subjects without shoulder pain. Isometric shoulder external rotation, at 0?? and 90?? abduction, and extension were performed at six loads. Dynamic shoulder flexion and abduction were performed at 70% maximum load. Results indicated that while surface and intramuscular electrodes record similar activation patterns when infraspinatus is moderately to highly activated (r and slope ??? 1), only intramuscular electrodes accurately reflected low (<10%MVC) infraspinatus activity (r=0.95 ?? 0.04, slope=15.6 ?? 16.3). The linear relationship between the activity recorded with surface and intramuscular electrodes when infraspinatus is moderately to highly active also indicated that intramuscular recordings from infraspinatus are representative of activity in the whole muscle. To ensure validity in reporting infraspinatus activation patterns when studying functional shoulder tasks in which infraspinatus may be relatively active and inactive at different phases of these tasks, intramuscular electrodes should be used to record infraspinatus activity.
%Z FOR Codes: 110603


%0 Journal Article
%~ PubMed
%A Whiteley, Rod
%A Adams, Roger
%A Ginn, Karen
%A Nicholson, Leslie
%T Playing level achieved, throwing history, and humeral torsion in Masters baseball players.
%B Journal of sports sciences
%D 2010
%C United Kingdom
%I Routledge
%V 28
%N 11
%P 1223-32
%@ 1466-447X
%X Humeral torsion is thought to be beneficial for throwing. To examine this hypothesis, the throwing and non-throwing arms of 84 Masters baseball players over 35 years of age were measured for humeral torsion, and the highest playing level they achieved and their playing history were recorded. Regression analyses were used to obtain predictors of the highest playing level achieved, throwing arm humeral torsion, and side-to-side difference in humeral torsion. Equations accounting for 36%, 46%, and 12% of the variance respectively were produced. Achieving representative level playing status was associated with the number of seasons played under 16 years of age and having greater throwing arm humeral retrotorsion. Throwing arm humeral retrotorsion was associated with non-throwing arm humeral retrotorsion and an increased number of seasons played before the age of 16 years. A model in which repeated throwing develops an adaptive unilateral bone torsion along with growth in baseball expertise is proposed. Thus dominant arm humeral retrotorsion is a predictor of highest baseball playing level achieved, which in turn is influenced by genetic endowment (as seen in the torsion of the non-throwing arm) and amount of throwing activity, particularly prior to the age of 16.
%Z FOR Codes: 110699


%0 Journal Article
%~ PubMed
%A Whiteley, Rod J
%A Adams, Roger D
%A Nicholson, Leslie L
%A Ginn, Karen A
%T Reduced humeral torsion predicts throwing-related injury in adolescent baseballers.
%B Journal of science and medicine in sport / Sports Medicine Australia
%D 2010
%C Australia
%I Elsevier
%V 13
%N 4
%P 392-6
%@ 1440-2440
%X The amount of torsion in the humerus is determined by both genetic and activity-related factors, and affects the external rotation range of motion available at the shoulder. Previous research has shown athletes participating in throwing sports to have a greater amount of humeral retrotorsion in their dominant arm. The purpose of this study was to investigate the predictive ability of both the genetic and activity-related aspects of humeral torsion regarding throwing-related injury. The amount of humeral torsion in both arms of 35 high level adolescent male baseballers (mean age 16.6 years+/-0.6 years) was measured at study commencement. Significantly increased humeral retrotorsion in the dominant arm compared to the non-dominant arm was found (p=0.04). These athletes were followed for a period of 30 months, and any injury to their throwing arm which resulted in missing either a game or practice was recorded. ROC curve analysis was used to determine the predictive ability of humeral torsion with respect to the occurrence of injury to the throwing arm. Of the 35 athletes, 19 suffered a throwing arm injury. AUC values derived from ROC analysis showed humeral torsion in the non-dominant arm (AUC: 0.679, 95% CI: 0.502-0.857), as well as the average of the humeral torsion in both arms (0.692, 0.512-0.873), to be predictive of injury. Torsion in the dominant arm was not a significant throwing arm injury predictor. Thus non-dominant arm humeral torsion (the genetic contribution) was found to be the predictor of throwing arm injury.
%Z FOR Codes: 1106


%0 Journal Article
%~ PubMed
%A Stuelcken, Max C
%A Ferdinands R, E D
%A Ginn, Karen A
%A Sinclair, Peter J
%T The Shoulder Distraction Force in Cricket Fast Bowling.
%B Journal of Applied Biomechanics
%D 2010
%C United States
%I Human Kinetics
%V 26
%N 3
%P 373-377
%@ 1065-8483
%X This preliminary study aimed to quantify the magnitude of the peak shoulder distraction force during the bowling action of female cricket fast bowlers. An eight camera Vicon motion analysis system operating at 120 Hz recorded the fast bowling actions of 18 Australian female fast bowlers. A three segment inverse solution model of the bowling arm was used to calculate the shoulder distraction force. A large peak shoulder distraction force was recorded during the early stages of the follow-through of the bowling action. When normalized for body weight, the distraction force was within the range of values reported for baseball and softball pitchers, who are considered to be at high risk of shoulder injury. Therefore, the relative importance of the peak shoulder distraction force in the fast bowling action for the development of shoulder pain in female cricket fast bowlers warrants further investigation.
%Z FOR Codes: 110601


%0 Journal Article
%~ PubMed
%A Boettcher, Craig E
%A Cathers, Ian
%A Ginn, Karen A
%T The role of shoulder muscles is task specific.
%B Journal of science and medicine in sport / Sports Medicine Australia
%D 2010
%C Australia
%I Elsevier Australia
%V 13
%N 6
%P 651-6
%@ 1878-1861
%X The aim of this study was to compare activity in shoulder muscles during unsupported internal and external rotation to examine their functional roles, and determine whether they retain their ''stabiliser'' or ''mover'' role regardless of the shoulder task. Electromyographic recordings in the dominant shoulder of 15 normal subjects were taken from 13 shoulder muscle sites using a combination of surface and intramuscular electrodes during isometric shoulder internal and external rotation in an unsupported abducted position under conditions of increasing load. During internal rotation significantly higher activity levels were found in subscapularis (p<0.001). During external rotation significantly higher activity levels were demonstrated in supraspinatus, infraspinatus, trapezius and serratus anterior (p<0.05). There were no significant differences in activity levels in deltoid, pectoralis major and latissimus dorsi during internal and external rotation. As rotational forces increased there was a significant increase in activity in all muscle sites activated above low levels (r(2)=0.93??0.07; mean??s.d.). This study has shown that shoulder muscle function is task specific and that shoulder muscle motor strategy for a particular task does not change with increasing torque. As the only shoulder rotators that demonstrated direction specificity the rotator cuff muscles are likely to be functioning to provide rotation torque while the deltoid is likely to be providing dynamic shoulder stability during the task examined. Higher scapulothoracic muscle activity during external rotation indicated the need for greater dynamic scapular stability as a result of higher rotator cuff activity during external than internal rotation.
%Z FOR Codes: 110603


%0 Journal Article
%~ PubMed
%A Reed, Darren
%A Halaki, Mark
%A Ginn, Karen
%T The rotator cuff muscles are activated at low levels during shoulder adduction: an experimental study.
%B Journal of Physiotherapy
%D 2010
%C Australia
%I Australian Physiotherapy Association
%V 56
%N 4
%P 259-264
%@ 1836-9553
%X Question: During isometric shoulder adduction in normal subjects, do the rotator cuff muscles activate more than other shoulder muscles? Are the activation patterns influenced by shoulder abduction angle or load? Design: A within-participant, repeated measures experimental study. Participants: 15 healthy adults. Intervention: Participants performed an isometric adduction exercise at 30??, 60??, and 90?? abduction in the scapular plane and at 25%, 50%, 75%, and 100% load. Outcome measures: During the exercises, a combination of indwelling and surface electromyographic recordings were taken from 11 shoulder muscles: supraspinatus, infraspinatus, subscapularis, pectoralis major, teres major, latissimus dorsi, rhomboid major, serratus anterior, lower trapezius, upper trapezius, and deltoid. Results: At 100% load, mean rotator cuff activation levels were low (supraspinatus at 3% of its maximum voluntary contraction, infraspinatus 27%, and subscapularis 27%) and significantly less than the activation levels of rhomboid major (81%), latissimus dorsi (103%), and teres major (76%) (F(10,140) = 15.5, p < 0.01). No significant difference in activity levels of the rotator cuff muscles were recorded when isometric adduction was performed at 30??, 60??, or 90?? abduction (p > 0.89). Among the muscles activated above minimum levels (> 10% of maximum voluntary contraction), mean activation levels increased as load increased (F(3,42) = 72.0, p < 0.01) Conclusion: Since isometric adduction in normal subjects does not produce moderate to high activation levels in any of the rotator cuff muscles tested, these results do not support the use of shoulder adduction to identify rotator cuff muscle dysfunction or strengthen the rotator cuff muscles.
%Z FOR Codes: 110603 110317


%0 Journal Article
%~ PubMed
%A Chen, Judy F
%A Ginn, Karen A
%A Herbert, Robert D
%T Passive mobilisation of shoulder region joints plus advice and exercise does not reduce pain and disability more than advice and exercise alone: a randomised trial.
%B Australian Journal of Physiotherapy
%D 2009
%C Australia
%I Australian Physiotherapy Association
%V 55
%N 1
%P 17-23
%@ 0004-9514
%X QUESTION: Is the addition of passive mobilisation of shoulder region joints to advice and exercise for patients with shoulder pain and stiffness more effective than advice and exercise alone? DESIGN: Randomised trial with concealed allocation, assessor blinding, and intention-to-treat analysis. PARTICIPANTS: 90 people who had shoulder pain and stiffness for more than one month. INTERVENTION: All participants received advice and exercise. The experimental group also received passive joint mobilisation of shoulder region joints. OUTCOME MEASURES: Primary outcome measures included pain and disability measured with the 13-point Shoulder Pain and Disability Index. Secondary outcome measures were self-perceived global improvement measured on a 6-point scale and active ranges of motion. Subjects received a maximum of 10 sessions of therapy. Outcome measurements were taken at baseline, one month, and six months. RESULTS: The experimental group had 3% (95% CI -5 to 11) less pain and disability than the control group at one month and 1% (95% CI -13 to 16) less pain at six months, which are statistically nonsignificant. Their global perceived effect was 0.1 out of 5 (95% CI -0.2 to 0.4) worse than the control group at one month and 0.1 (95% CI -0.5 to 0.7) better at 6 months, which are also statistically non-significant. Differences between groups in all range of motion measures were small and statistically non-significant. CONCLUSION: The addition of passive joint mobilisation of shoulder region joints is not more effective than advice and exercise alone for shoulder pain and stiffness. Trial registration: ACTRN 12605000080628.
%Z FOR Codes: 110317


%0 Journal Article
%~ PubMed
%A Whiteley, Rod J
%A Ginn, Karen A
%A Nicholson, Leslie L
%A Adams, Roger D
%T Sports participation and humeral torsion.
%B Journal of Orthopaedic and Sports Physical Therapy
%D 2009
%C United States
%I American Physical Therapy Association
%V 39
%N 4
%P 256-263
%@ 0190-6011
%X STUDY DESIGN: Cross-sectional study. OBJECTIVE: To examine differences between arms in humeral torsion in adult and adolescent throwing and nonthrowing athletes, and nonathletic adults. BACKGROUND: It is hypothesized that humeral retrotorsion develops by, and is beneficial for, throwing. Thus throwers should demonstrate greater retrotorsion in their dominant arm relative to their nondominant arm and have more side-to-side retrotorsion difference than nonthrowing groups. In addition, adult throwers should have a greater side-to-side retrotorsion difference than adolescent throwers, and swimmers should not demonstrate a retrotorsion difference. METHODS AND MEASURES: Using ultrasound to standardize the location of the bicipital groove, the amount of humeral torsion was measured in both arms of male baseball players (85 adult, 35 adolescent), female softball players (16 adult, 37 adolescent), 29 elite adolescent swimmers (19 female), and 16 nonathletic adults (8 female). RESULTS: More retrotorsion was found in the dominant arm of almost all throwing athletes, irrespective of their gender or whether they were adults or adolescents (mean+/-SD side-to-side difference, 11.9 degrees+/-10.5 degrees). This difference was less for swimmers (6.4 degrees+/-9.9 degrees) and nonathletic adults (1.3 degrees+/-8.9 degrees). CONCLUSION: Greater dominant armhumeral retrotorsion is observed contingent with participation in throwing sports.
%Z FOR Codes: 110699


%0 Journal Article
%~ PubMed
%A Boettcher, Craig E
%A Ginn, Karen A
%A Cathers, Ian
%T The 'empty can' and 'full can' tests do not selectively activate supraspinatus.
%B Journal of science and medicine in sport / Sports Medicine Australia
%D 2009
%C Australia
%I Elsevier
%V 12
%N 0
%P 435-9
%@ 1440-2440
%X Based on previous electromyographic studies the ''empty can'' (EC) and ''full can'' (FC) tests have been promoted as being able to isolate activity to supraspinatus and are therefore diagnostic of supraspinatus dysfunction. However, there is evidence to suggest that these positions do not selectively activate supraspinatus, and that they may have poor diagnostic accuracy, bringing into question the validity of these tests. Due to limitations in the original EMG papers describing the EC and FC tests the current study aimed to further examine shoulder muscle activity during these tests to determine their ability to selectively activate supraspinatus. EMG activity was recorded from 13 muscles in 15 normal subjects while performing these two tests. Results showed that during the EC and FC muscle tests nine and eight other shoulder muscles, respectively, were equally highly activated as supraspinatus. It was concluded from these results that the EC and FC tests do not primarily activate supraspinatus with minimal activation from other shoulder muscles and therefore, do not satisfy basic criteria to be valid diagnostic tools for supraspinatus pathology. Therefore, these tests should not be interpreted as definitive tests for the clinical diagnosis of supraspinatus pathology. They may, however, be beneficial during shoulder muscle strengthening programs.
%Z FOR Codes: 110604 110317


%0 Journal Article
%~ PubMed
%A Boettcher, Craig
%A Ginn, Karen
%A Cathers, Ian
%T Which is the Optimal Exercise to Strengthen Supraspinatus?
%B Medicine and science in sports and exercise
%D 2009
%C United States
%I Lippincott Williams & Wilkins
%V 41
%N 11
%P 1979-83
%@ 0195-9131
%X Supraspinatus strengthening is an important part of shoulder rehabilitation programs. Because of the force-couple relationship between supraspinatus and deltoid during shoulder abduction, it has been proposed that the optimal exercise to strengthen supraspinatus is one that would maximize supraspinatus activity while minimizing surrounding muscle activity, particularly deltoid. The aim of this study was to simultaneously examine all exercises known to recruit supraspinatus at high levels and to compare the level of recruitment in supraspinatus, deltoid, and infraspinatus.
%Z FOR Codes: 110203 1106 1103


%0 Journal Article
%~ PubMed
%A Stuelcken, Max C
%A Ginn, Karen A
%A Sinclair, Peter J
%T Musculoskeletal profile of the lumbar spine and hip regions in cricket fast bowlers.
%B Physical Therapy in Sport
%D 2008
%C United Kingdom
%I Churchill Livingstone
%V 9
%N 2
%P 82-88
%@ 1873-1600
%X OBJECTIVES: To determine the career history of low back pain (LBP) in current elite female cricket fast bowlers and then compare measures of lumbar spine and hip range of motion (ROM) and trunk extensor endurance between those bowlers with and without a history of LBP. Measures for the female bowlers were also compared to a small sample of male fast bowlers. PARTICIPANTS: Twenty-six elite female fast bowlers and eight male fast bowlers of similar age and bowling experience. MAIN OUTCOME MEASURES: The career history of LBP was determined by a self-administered questionnaire and by accessing medical records. Range of motion measures for the lumbar spine and hips were obtained using inclinometry or goniometry. Trunk extensor endurance was assessed using a modified Sorensen test. RESULTS: Fourteen female fast bowlers had a history of LBP. There was a significant difference in lumbar lateral flexion ROM to the bowling arm side between those female fast bowlers with and without a history of LBP (p0.05). The female fast bowlers had significantly more bilateral hip extension ROM (p0.05) compared to the male fast bowlers. CONCLUSIONS: This information should be useful for practitioners involved in the conditioning and rehabilitation of cricketers. Future prospective studies should investigate potential predictors of LBP in female fast bowlers.
%Z FOR Codes: 110699


%0 Journal Article
%~ PubMed
%A Whiteley, R J
%A Adams, R D
%A Nicholson, L L
%A Ginn, K A
%T Shoulder proprioception is associated with humeral torsion in adolescent baseball players.
%B Physical therapy in sport
%D 2008
%C United Kingdom
%I Churchill Livingstone
%V 9
%N 4
%P 177-184
%@ 1873-1600
%X OBJECTIVES: To determine the relationship between the amount of humeral torsion and a measure of active proprioception in adolescent male throwing athletes. DESIGN: Cross-sectional laboratory study with uninjured subjects. SETTING: University of Sydney and NSW Institute of Sport. PARTICIPANTS: Participants were 16 adolescent male baseball players (15.0-18.1 years old, SD=16.3) holding baseball scholarships at the NSW Institute of Sport. MAIN OUTCOME MEASURES: The main outcome measures, active proprioception (shoulder rotation, in 90 degrees of arm abduction moving towards external rotation, using the Active Movement Extent Discriminating Apparatus) and humeral torsion (using an ultrasound-assisted method), were measured bilaterally. RESULTS: A strong (r=0.88) and significant (p=0.001) correlation was found between increasing humeral retrotorsion and better active proprioceptive acuity in the non-dominant arm, while the relation was weaker (r=0.41) and did not reach statistical significance (p=0.120) for the dominant arm. CONCLUSIONS: A cognitive processing capacity model, which suggests that greater humeral retrotorsion reduces neural processing requirements, has been proposed to explain the direct relationship between proprioceptive acuity and humeral retrotorsion.
%Z FOR Codes: 110604 110906


%0 Journal Article
%~ PubMed
%A Stuelcken, Max C
%A Ginn, Karen A
%A Sinclair, Peter J
%T Shoulder strength and range of motion in elite female cricket fast bowlers with and without a history of shoulder pain.
%B Journal of science and medicine in sport / Sports Medicine Australia
%D 2008
%C Australia
%I Sports Medicine Australia
%V 11
%N 6
%P 575-80
%@ 1440-2440
%X This study aimed to determine the prevalence of shoulder pain in female cricket fast bowlers and compare the shoulder rotation range of motion and strength of those bowlers with and without a history of shoulder pain. The active range of motion and isokinetic strength of the shoulder internal and external rotators was assessed in the bowling and non-bowling shoulders of 26 elite Australian female fast bowlers. Twelve bowlers had a history of shoulder pain. There were significant bilateral differences in external rotation range of motion for those bowlers without a history of shoulder pain (p<0.05), and in internal rotation range of motion for both the total cohort and those bowlers with a history of shoulder pain (p<0.05). There were no bilateral differences in average torques or average torque ratios, nor were there any differences in rotation range of motion, torques or torque ratios in the bowling shoulder between bowlers with and without a history of shoulder pain. There was an association between concentric internal rotation torque for the bowling shoulder and years of fast bowling (r(s)=0.45). Given the relatively small number of elite female cricketers, future research in this field will need to recruit fast bowlers from other cricket playing nations to increase the power of studies and provide more confidence in the statistical outcomes.
%Z FOR Codes: 110604


%0 Journal Article
%~ PubMed
%A Boettcher, Craig E
%A Ginn, Karen A
%A Cathers, Ian
%T Standard maximum isometric voluntary contraction tests for normalizing shoulder muscle EMG.
%B Journal of Orthopaedic Research
%D 2008
%C United States
%I John Wiley & Sons
%V 26
%N 12
%P 1591-1597
%@ 1554-527X
%X A comparison of electromyographic (EMG) activity of muscles between and within subjects, and during separate occasions of testing, requires normalization. The most common way for generating the reference level used for normalizing shoulder EMG data is with a maximum isometric voluntary contraction (MVIC). The purpose of this study was to develop a parsimonious set of standardized tests that generate an MVIC in all the major muscle groups of the shoulder. Twelve muscles of the dominant shoulder of 15 subjects were examined using a combination of surface and intramuscular electrodes during 15 tests. The results indicated that many tests maximally activated more than one muscle simultaneously. Four tests were identified as being sufficient for generating an MVIC in the 12 muscles examined and are recommended as the standard set for normalizing shoulder muscle EMG: abduction 90 degrees with internal rotation ("empty can"), internal rotation in 90 degrees abduction ("internal rotation 90 degrees"), flexion at 125 degrees with scapula resistance ("flexion 125 degrees"), and horizontal adduction at 90 degrees flexion ("palm press"). The use of these shoulder normalization tests will make comparisons between shoulder EMG studies more reliable.
%Z FOR Codes: 110603 110999 110314


%0 Journal Article
%~ PubMed
%A Dark, Alanna
%A Ginn, Karen A
%A Halaki, Mark
%T Shoulder Muscle Recruitment Patterns During Commonly Used Rotator Cuff Exercises: An Electromyographic Study.
%B Physical therapy
%D 2007
%C United States
%I American Physical Therapy Association
%V 87
%N 8
%P 1039-46
%@ 0031-9023
%X Graduated rotation exercises performed with the arm by the side are commonly used to improve rotator cuff (RC) muscle function. The aim of this study was to compare the pattern of recruitment of the RC muscles with that of other shoulder muscles that rotate the shoulder joint during these exercises.
%Z FOR Codes: 110604