Background Micro-traumatic posterior shoulder instability (PSI) is an often missed and misdiagnos... more Background Micro-traumatic posterior shoulder instability (PSI) is an often missed and misdiagnosed pathology presenting in tennis players. The aetiology of micro-traumatic PSI in tennis players is multifactorial, including congenital factors, loss of strength and motor control, and sport-specific repetitive microtrauma. Repetitive forces placed on the dominant shoulder, particularly combinations of flexion, horizontal adduction, and internal rotation contribute to the microtrauma. These positions are characteristic for kick serves, backhand volleys, and the follow-through phase of forehands and serves. The aim of this clinical commentary is to present an overview of the aetiology, classification, clinical presentation, and treatment of micro-traumatic PSI, with a particular focus on tennis players. Level of Evidence 5
Multidirectional instability (MDI) of the glenohumeral joint refers to symptomatic subluxations o... more Multidirectional instability (MDI) of the glenohumeral joint refers to symptomatic subluxations or dislocations in more than one direction. The aetiology of MDI is multifactorial, which makes the classification of this condition challenging. A shoulder rehabilitation program is the initial recommended treatment for MDI, however available rehabilitation programs have varying levels of evidence to support their effectiveness. In 2016, we published the details of an evidence-based program for MDI that has been evaluated for efficacy in two single-group studies and a randomised controlled trial. In 2017, we published a clinical commentary on the aetiology, classification, and treatment of this condition. The aim of this paper is to provide an update on the components of these publications with a particular focus on new advances in the non-operative management of this condition.
SUMMARY. The brachial plexus tension test (BPTT) is used clinically to test the dynamics of the n... more SUMMARY. The brachial plexus tension test (BPTT) is used clinically to test the dynamics of the neural tissues of the upper quadrant. The upper trapezius muscle and the nerves of the brachial plexus share common anatomical locations and are jointly affected by BPTT movements. This study investigated the relationship between the BPTT, upper trapezius muscle activity and range of neural tissue extensibility in asymptomatic subjects. Normal male subjects with greater and lesser neural tissue extensibility were tested. Results revealed that those with lesser neural extensibility exhibited significantly greater upper trapezius muscle activity during discrete BPTT stages. There was no difference between groups in the levels of pain perceived with the test. These results suggest that asymptomatic neural tissues are protected from stretch by muscle activity not solely mediated by pain but also possibly mediated by stretch receptors in neural structures. Copyright 1997 Harcourt Publishers Ltd.
The purpose of this study was to establish the intra-rater and inter-rater reliability of isometr... more The purpose of this study was to establish the intra-rater and inter-rater reliability of isometric shoulder strength assessment using a hand-held dynamometer (HHD) in functional joint positions in student circus artists with symptomatic atraumatic shoulder instability. METHODS Over two testing sessions, two experienced physiotherapists assessed the shoulder strength of 24 student circus artists with clinically diagnosed atraumatic shoulder instability. Both the symptomatic and asymptomatic shoulder was assessed using a HHD in 10 functional positions. Intra-class correlation coefficients (ICCs) were calculated to determine the reliability of strength measurements. RESULTS All examined positions showed moderate-high intra-rater and inter-rater reliability. External rotation at 0° and internal rotation in horizontal flexion at 45° revealed the most reliable results, and the shrug position the least reliable. Inter-rater and intra-rater reliability was high and demonstrated similar res...
Introduction: A modification to standard rotator cuff exercises that uses anelastic resistanceban... more Introduction: A modification to standard rotator cuff exercises that uses anelastic resistancebandaround thehumeral head to create an anterior translational force is proposed to improve humeral head centralisation by facilitating co-contraction of the rotator cuff to resist the force. A balance between co-activation and muscle intensity of the rotator cuff is considered essential for optimal humeral head stability, correct axial alignment, concavity compression and normal shoulder function. The aim of this study was to determine if the modified internal and external rotation exercises increase activation of the rotator cuff when compared to standard rotation exercises. Methods: Intramuscular electrodeswereused to record themuscle activity of the infraspinatus, supraspinatus and subscapularis in the dominant shoulders of ten healthy individuals (mean age 22.8 years). Participants completed8 repetitions of eachof the exercises. Twelve sets of exerciseswereperformed in randomorder: standard and modified internal rotation at 0, 45 and 90 degrees abduction and standard andmodified external rotation at 0, 45 and90degrees of abduction. Results: Subscapularis activated at a higher intensity during the modified exercises overall, however only external rotation at 0 degrees of abduction reached significance (p=0.03). No significant differences were found in supraspinatus and infraspinatus muscle activity between the standard and modified exercises (p>0.05). Discussion: The modified exercises may elicit greater muscle activity in anterior cuff muscle in a normal population. This simple modification may promote increased dynamic stability when performing rotator cuff exercises. It has been shown previously using biomechanical and cadaveric modeling that during external rotation at 0 degrees of abduction, the subscapularis muscle is the most important stabiliser of the glenohumeral joint. Increasing the anterior translational force on the humeral head using the modified exercise in this position promotes greater subscapularis activity andco-activationof the rotator cuff. Considering the testing was performed in a normal population where passive constraints of the joint can also help to stabilise the humeral head, testing in a pathological group with increased glenohumeral laxity could elicit potentially greater differences between exercises. The current study provides preliminary validity for the use of these simple, modified exercises to elicit greater subscapularis muscle activity in the clinical setting.
Posterior shoulder instability is recognised as being less prevalent than anterior instability, h... more Posterior shoulder instability is recognised as being less prevalent than anterior instability, however the diagnosis of this pathology is easily overlooked or missed and this may contribute to an underestimation of prevalence. Recently, there has been increasing recognition of this condition and consequently a greater requirement for knowledge of diagnostic procedures and treatment directions. Currently there is limited research into the conservative management of posterior instability, although it is recommended as first-line treatment prior to surgical review, particularly in those with an atraumatic instability mechanism. The aim of this paper is to outline a comprehensive rehabilitation program for the conservative management of posterior instability with a focus on scapular and humeral head control. The information provided includes extensive written information, flowcharts, figures and a table of management parameters that will provide therapists with adequate detail to replicate the program in the clinical setting.
Conservative management is commonly recommended as the first-line treatment for multidirectional ... more Conservative management is commonly recommended as the first-line treatment for multidirectional instability (MDI) of the shoulder. Despite this, the evidence for efficacy of treatment is limited, and until recently, guidance for clinicians on conservative rehabilitation programs has been inadequate. This study evaluated the effectiveness of a physiotherapy-led exercise program for participants with MDI. In a single-group study design, 43 participants (16 male, 27 female; mean age, 19.8 years, standard deviation, 4.9 years) diagnosed with MDI undertook a 12-week exercise program. Primary outcome measures were the Melbourne Instability Shoulder Score, Western Ontario Shoulder Instability Index, and Oxford Shoulder Instability Score. Secondary outcomes were strength and scapular position. All measures were taken at baseline and repeated at the conclusion of the program. Test differences before and after rehabilitation were evaluated with dependent t tests and single-group effect size calculations (standardized mean difference [SMD]) to provide a measure of the magnitude of the difference. Large effects were found between pre- and postrehabilitation scores on all functional instability questionnaires, with the Western Ontario Shoulder Instability Index demonstrating the largest effect (SMD, -3.04). Scapular upward rotation improved significantly in the early ranges of abduction (0°-60°), with moderate to large effects (SMDs, 0.54-0.95). All strength measures significantly improved, with large differences identified (SMDs, 0.69-2.08). The identified improvement in functional status, shoulder muscle strength, and scapular positioning after rehabilitation allows greater confidence in the value of conservative management of MDI and informs further research by way of clinical trials in the area.
Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine, Jan 22, 2016
Acute latissimus dorsi tendon injuries are uncommon, having not previously been described in cric... more Acute latissimus dorsi tendon injuries are uncommon, having not previously been described in cricketers. The leg spinner's stock ball bowling technique and the fast bowler's back-of-the-hand slow ball, which is used much more widely in T20 cricket, produce a significant eccentric contraction load on the latissimus dorsi muscle. A retrospective review of a case series of acute latissimus dorsi tendon injuries in 3 elite cricketers (2 fast bowlers and a leg-spin bowler). We compare the outcomes using patient-rated scales and objective strength testing. Two patients underwent operative repair and had excellent outcomes. One of the nonoperatively managed patients had mild ongoing symptoms at 7 months. An associated injury to teres major did not affect the outcome of this injury. Operative repair is a viable alternative and may produce better outcomes in cricketers. The short T20 form of cricket has lead to an increase in the number of back-of-the-hand slow balls, a risk factor f...
The recommended initial treatment for multidirectional instability (MDI) of the shoulder is a reh... more The recommended initial treatment for multidirectional instability (MDI) of the shoulder is a rehabilitation program, yet there is very low-quality evidence to support this approach. Purpose/Hypothesis: The purpose was to compare the Watson MDI program and Rockwood Instability program among patients with nontraumatic, nonstructural MDI. The hypothesis was that the Watson MDI program would produce clinically and statistically superior outcomes over the Rockwood Instability program. Randomized controlled trial; Level of evidence, 2. Forty-one participants with MDI were randomly allocated to the Watson MDI or Rockwood Instability program. Participants attended 12 weekly physiotherapy sessions for exercise prescription. Outcomes were assessed at baseline and 6, 12, and 24 weeks after randomization. Primary outcomes were the Melbourne Instability Shoulder Score (MISS) and the Western Ontario Shoulder Index (WOSI). Secondary outcomes included the Orebro Musculoskeletal Pain Questionnaire,...
The most commonly recommended initial treatment for multidirectional instability is a rehabilitat... more The most commonly recommended initial treatment for multidirectional instability is a rehabilitation program. Although there is evidence to support the effect of conservative management on this condition, the published literature provides little information on the exercise parameters of such programs. In addition, current published rehabilitation programs for multidirectional instability do not focus on scapula stability or exercise drills into functional and sports-specific positions, which are often important aspects to consider in this patient population. The aim of this paper (Part 1) is to outline the first two stages of a six-stage rehabilitation program for the conservative management of multidirectional instability with a focus on scapula control and exercise drills into functional positions. This clinical protocol is currently being tested for efficacy as part of a randomized controlled trial (Australian New Zealand Clinical Trials Registry #ACTRN12613001240730). The inform...
The most commonly recommended treatment for multidirectional instability (MDI) of the shoulder is... more The most commonly recommended treatment for multidirectional instability (MDI) of the shoulder is exercise. Despite this recommendation, there is limited evidence to support the effectiveness of exercise. The aim of this paper is to describe a pilot randomised controlled trial comparing the effectiveness of 2 exercise programmes on outcomes of participants with MDI. Consenting participants between 12 and 35 years, with non-traumatic MDI will be randomly allocated to participate in either the Rockwood Instability programme or the Watson MDI programme. Both programmes involve 1 consultation per week for 12 weeks with a physiotherapist to prescribe and progress a home exercise programme. Outcomes will be assessed at baseline, 6, 12, 24 and 52 weeks. Primary outcome measures include the Melbourne Instability Shoulder Score and Western Ontario Shoulder Index. Secondary outcomes include scapular coordinates, scapular upward rotation angles, muscle strength, symptomatic onset, limiting factor and angle of limiting factor in abduction range, incidence of complete glenohumeral joint dislocation, global rating of change, satisfaction scores, the Orebro Musculoskeletal Pain Questionnaire, adverse events and compliance with the home exercise programme. Data will be analysed on intention-to-treat principles and a per protocol basis. This trial will evaluate whether there are differences in outcomes between the Rockwood and the Watson MDI programmes for participants with MDI. Participant confidentiality will be maintained with publication of results. Ethics approval: Faculty of Health Sciences (FHEC12/201). ACTRN12613001240730; Pre-results.
Background Micro-traumatic posterior shoulder instability (PSI) is an often missed and misdiagnos... more Background Micro-traumatic posterior shoulder instability (PSI) is an often missed and misdiagnosed pathology presenting in tennis players. The aetiology of micro-traumatic PSI in tennis players is multifactorial, including congenital factors, loss of strength and motor control, and sport-specific repetitive microtrauma. Repetitive forces placed on the dominant shoulder, particularly combinations of flexion, horizontal adduction, and internal rotation contribute to the microtrauma. These positions are characteristic for kick serves, backhand volleys, and the follow-through phase of forehands and serves. The aim of this clinical commentary is to present an overview of the aetiology, classification, clinical presentation, and treatment of micro-traumatic PSI, with a particular focus on tennis players. Level of Evidence 5
Multidirectional instability (MDI) of the glenohumeral joint refers to symptomatic subluxations o... more Multidirectional instability (MDI) of the glenohumeral joint refers to symptomatic subluxations or dislocations in more than one direction. The aetiology of MDI is multifactorial, which makes the classification of this condition challenging. A shoulder rehabilitation program is the initial recommended treatment for MDI, however available rehabilitation programs have varying levels of evidence to support their effectiveness. In 2016, we published the details of an evidence-based program for MDI that has been evaluated for efficacy in two single-group studies and a randomised controlled trial. In 2017, we published a clinical commentary on the aetiology, classification, and treatment of this condition. The aim of this paper is to provide an update on the components of these publications with a particular focus on new advances in the non-operative management of this condition.
SUMMARY. The brachial plexus tension test (BPTT) is used clinically to test the dynamics of the n... more SUMMARY. The brachial plexus tension test (BPTT) is used clinically to test the dynamics of the neural tissues of the upper quadrant. The upper trapezius muscle and the nerves of the brachial plexus share common anatomical locations and are jointly affected by BPTT movements. This study investigated the relationship between the BPTT, upper trapezius muscle activity and range of neural tissue extensibility in asymptomatic subjects. Normal male subjects with greater and lesser neural tissue extensibility were tested. Results revealed that those with lesser neural extensibility exhibited significantly greater upper trapezius muscle activity during discrete BPTT stages. There was no difference between groups in the levels of pain perceived with the test. These results suggest that asymptomatic neural tissues are protected from stretch by muscle activity not solely mediated by pain but also possibly mediated by stretch receptors in neural structures. Copyright 1997 Harcourt Publishers Ltd.
The purpose of this study was to establish the intra-rater and inter-rater reliability of isometr... more The purpose of this study was to establish the intra-rater and inter-rater reliability of isometric shoulder strength assessment using a hand-held dynamometer (HHD) in functional joint positions in student circus artists with symptomatic atraumatic shoulder instability. METHODS Over two testing sessions, two experienced physiotherapists assessed the shoulder strength of 24 student circus artists with clinically diagnosed atraumatic shoulder instability. Both the symptomatic and asymptomatic shoulder was assessed using a HHD in 10 functional positions. Intra-class correlation coefficients (ICCs) were calculated to determine the reliability of strength measurements. RESULTS All examined positions showed moderate-high intra-rater and inter-rater reliability. External rotation at 0° and internal rotation in horizontal flexion at 45° revealed the most reliable results, and the shrug position the least reliable. Inter-rater and intra-rater reliability was high and demonstrated similar res...
Introduction: A modification to standard rotator cuff exercises that uses anelastic resistanceban... more Introduction: A modification to standard rotator cuff exercises that uses anelastic resistancebandaround thehumeral head to create an anterior translational force is proposed to improve humeral head centralisation by facilitating co-contraction of the rotator cuff to resist the force. A balance between co-activation and muscle intensity of the rotator cuff is considered essential for optimal humeral head stability, correct axial alignment, concavity compression and normal shoulder function. The aim of this study was to determine if the modified internal and external rotation exercises increase activation of the rotator cuff when compared to standard rotation exercises. Methods: Intramuscular electrodeswereused to record themuscle activity of the infraspinatus, supraspinatus and subscapularis in the dominant shoulders of ten healthy individuals (mean age 22.8 years). Participants completed8 repetitions of eachof the exercises. Twelve sets of exerciseswereperformed in randomorder: standard and modified internal rotation at 0, 45 and 90 degrees abduction and standard andmodified external rotation at 0, 45 and90degrees of abduction. Results: Subscapularis activated at a higher intensity during the modified exercises overall, however only external rotation at 0 degrees of abduction reached significance (p=0.03). No significant differences were found in supraspinatus and infraspinatus muscle activity between the standard and modified exercises (p>0.05). Discussion: The modified exercises may elicit greater muscle activity in anterior cuff muscle in a normal population. This simple modification may promote increased dynamic stability when performing rotator cuff exercises. It has been shown previously using biomechanical and cadaveric modeling that during external rotation at 0 degrees of abduction, the subscapularis muscle is the most important stabiliser of the glenohumeral joint. Increasing the anterior translational force on the humeral head using the modified exercise in this position promotes greater subscapularis activity andco-activationof the rotator cuff. Considering the testing was performed in a normal population where passive constraints of the joint can also help to stabilise the humeral head, testing in a pathological group with increased glenohumeral laxity could elicit potentially greater differences between exercises. The current study provides preliminary validity for the use of these simple, modified exercises to elicit greater subscapularis muscle activity in the clinical setting.
Posterior shoulder instability is recognised as being less prevalent than anterior instability, h... more Posterior shoulder instability is recognised as being less prevalent than anterior instability, however the diagnosis of this pathology is easily overlooked or missed and this may contribute to an underestimation of prevalence. Recently, there has been increasing recognition of this condition and consequently a greater requirement for knowledge of diagnostic procedures and treatment directions. Currently there is limited research into the conservative management of posterior instability, although it is recommended as first-line treatment prior to surgical review, particularly in those with an atraumatic instability mechanism. The aim of this paper is to outline a comprehensive rehabilitation program for the conservative management of posterior instability with a focus on scapular and humeral head control. The information provided includes extensive written information, flowcharts, figures and a table of management parameters that will provide therapists with adequate detail to replicate the program in the clinical setting.
Conservative management is commonly recommended as the first-line treatment for multidirectional ... more Conservative management is commonly recommended as the first-line treatment for multidirectional instability (MDI) of the shoulder. Despite this, the evidence for efficacy of treatment is limited, and until recently, guidance for clinicians on conservative rehabilitation programs has been inadequate. This study evaluated the effectiveness of a physiotherapy-led exercise program for participants with MDI. In a single-group study design, 43 participants (16 male, 27 female; mean age, 19.8 years, standard deviation, 4.9 years) diagnosed with MDI undertook a 12-week exercise program. Primary outcome measures were the Melbourne Instability Shoulder Score, Western Ontario Shoulder Instability Index, and Oxford Shoulder Instability Score. Secondary outcomes were strength and scapular position. All measures were taken at baseline and repeated at the conclusion of the program. Test differences before and after rehabilitation were evaluated with dependent t tests and single-group effect size calculations (standardized mean difference [SMD]) to provide a measure of the magnitude of the difference. Large effects were found between pre- and postrehabilitation scores on all functional instability questionnaires, with the Western Ontario Shoulder Instability Index demonstrating the largest effect (SMD, -3.04). Scapular upward rotation improved significantly in the early ranges of abduction (0°-60°), with moderate to large effects (SMDs, 0.54-0.95). All strength measures significantly improved, with large differences identified (SMDs, 0.69-2.08). The identified improvement in functional status, shoulder muscle strength, and scapular positioning after rehabilitation allows greater confidence in the value of conservative management of MDI and informs further research by way of clinical trials in the area.
Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine, Jan 22, 2016
Acute latissimus dorsi tendon injuries are uncommon, having not previously been described in cric... more Acute latissimus dorsi tendon injuries are uncommon, having not previously been described in cricketers. The leg spinner's stock ball bowling technique and the fast bowler's back-of-the-hand slow ball, which is used much more widely in T20 cricket, produce a significant eccentric contraction load on the latissimus dorsi muscle. A retrospective review of a case series of acute latissimus dorsi tendon injuries in 3 elite cricketers (2 fast bowlers and a leg-spin bowler). We compare the outcomes using patient-rated scales and objective strength testing. Two patients underwent operative repair and had excellent outcomes. One of the nonoperatively managed patients had mild ongoing symptoms at 7 months. An associated injury to teres major did not affect the outcome of this injury. Operative repair is a viable alternative and may produce better outcomes in cricketers. The short T20 form of cricket has lead to an increase in the number of back-of-the-hand slow balls, a risk factor f...
The recommended initial treatment for multidirectional instability (MDI) of the shoulder is a reh... more The recommended initial treatment for multidirectional instability (MDI) of the shoulder is a rehabilitation program, yet there is very low-quality evidence to support this approach. Purpose/Hypothesis: The purpose was to compare the Watson MDI program and Rockwood Instability program among patients with nontraumatic, nonstructural MDI. The hypothesis was that the Watson MDI program would produce clinically and statistically superior outcomes over the Rockwood Instability program. Randomized controlled trial; Level of evidence, 2. Forty-one participants with MDI were randomly allocated to the Watson MDI or Rockwood Instability program. Participants attended 12 weekly physiotherapy sessions for exercise prescription. Outcomes were assessed at baseline and 6, 12, and 24 weeks after randomization. Primary outcomes were the Melbourne Instability Shoulder Score (MISS) and the Western Ontario Shoulder Index (WOSI). Secondary outcomes included the Orebro Musculoskeletal Pain Questionnaire,...
The most commonly recommended initial treatment for multidirectional instability is a rehabilitat... more The most commonly recommended initial treatment for multidirectional instability is a rehabilitation program. Although there is evidence to support the effect of conservative management on this condition, the published literature provides little information on the exercise parameters of such programs. In addition, current published rehabilitation programs for multidirectional instability do not focus on scapula stability or exercise drills into functional and sports-specific positions, which are often important aspects to consider in this patient population. The aim of this paper (Part 1) is to outline the first two stages of a six-stage rehabilitation program for the conservative management of multidirectional instability with a focus on scapula control and exercise drills into functional positions. This clinical protocol is currently being tested for efficacy as part of a randomized controlled trial (Australian New Zealand Clinical Trials Registry #ACTRN12613001240730). The inform...
The most commonly recommended treatment for multidirectional instability (MDI) of the shoulder is... more The most commonly recommended treatment for multidirectional instability (MDI) of the shoulder is exercise. Despite this recommendation, there is limited evidence to support the effectiveness of exercise. The aim of this paper is to describe a pilot randomised controlled trial comparing the effectiveness of 2 exercise programmes on outcomes of participants with MDI. Consenting participants between 12 and 35 years, with non-traumatic MDI will be randomly allocated to participate in either the Rockwood Instability programme or the Watson MDI programme. Both programmes involve 1 consultation per week for 12 weeks with a physiotherapist to prescribe and progress a home exercise programme. Outcomes will be assessed at baseline, 6, 12, 24 and 52 weeks. Primary outcome measures include the Melbourne Instability Shoulder Score and Western Ontario Shoulder Index. Secondary outcomes include scapular coordinates, scapular upward rotation angles, muscle strength, symptomatic onset, limiting factor and angle of limiting factor in abduction range, incidence of complete glenohumeral joint dislocation, global rating of change, satisfaction scores, the Orebro Musculoskeletal Pain Questionnaire, adverse events and compliance with the home exercise programme. Data will be analysed on intention-to-treat principles and a per protocol basis. This trial will evaluate whether there are differences in outcomes between the Rockwood and the Watson MDI programmes for participants with MDI. Participant confidentiality will be maintained with publication of results. Ethics approval: Faculty of Health Sciences (FHEC12/201). ACTRN12613001240730; Pre-results.
Uploads
Papers by Simon Balster