The role of the scapula

Analysis of abduction moment arms after rotator cuff tear and acellular dermal matrix allograft reconstruction

BACKGROUND

Biomechanical testing of abduction moment arms presents a useful method to assess the contributions of individual rotator cuff muscles to glenohumeral function. This study aimed to investigate the changes in abduction moment arms after the treatment of supraspinatus tears with superior capsular reconstruction (SCR), bursal acromial reconstruction (BAR), and a combined SCR-BAR procedure, all with human dermal allograft.

METHODS

We tested 7 fresh-frozen cadaveric specimens under 6 conditions: (1) intact, (2) 50% supraspinatus tear (partial tear), (3) 100% supraspinatus tear, (4) SCR, (5) SCR combined with BAR, and (6) BAR. In each condition, the moment arms for the individual muscles of the teres minor, subscapularis, and infraspinatus were calculated throughout 90° of abduction using a motion capture system. Analysis of variance and post hoc Tukey testing were performed to determine significance.

RESULTS

In the teres minor, the moment arms in the SCR (11.9 mm), BAR (10.1 mm), and SCR-BAR (11.9 mm) conditions were greater than those in the intact (8.5 mm; P = .001, P = .001, and P = .001, respectively), partial tear (9.1 mm; P = .001, P = .128, and P = .001, respectively), and complete tear (8.8 mm; P = .001, P = .011, and P = .001, respectively) conditions. Similarly, in the subscapularis, the moment arms in the SCR (13.4 mm), BAR (13.8 mm), and SCR-BAR (13.5 mm) conditions were greater than those in the intact (10.6 mm; P = .006, P = .001, and P = .003, respectively) and partial tear (10.4 mm; P = .006, P = .001, and P = .003, respectively) conditions. In the teres minor, the SCR (11.9 mm) and SCR-BAR (11.9 mm) conditions were also found to have significantly increased moment arms compared with the BAR condition (10.1 mm; P = .001 and P = .001, respectively). In the infraspinatus, the BAR condition (13.8 mm) was found to have a significantly decreased moment arm compared with the partial tear condition (15.8 mm, P = .026), with no other significant findings between conditions.

CONCLUSION

Our results suggest that the moment arm contributions of the individual muscles comprising the rotator cuff can change after reconstruction to compensate for tears. SCR and SCR-BAR increase the moment arms in the teres minor and subscapularis, potentially allowing for increased abduction ability.

Comparison of the physiotherapy with and without focus on the scapulothoracic joint on pain, range of motion, functional disability, quality of life, and treatment effectiveness of patients after arthroscopic shoulder rotator cuff tendon repair: A randomized controlled trial with short-term follow-up

BACKGROUND

Rotator cuff tears are prevalent shoulder injuries, significantly affecting shoulder stabilization and patient quality of life. Despite rehabilitation efforts post-arthroscopic surgery, the efficacy of scapular-focused exercises remains uncertain with limited supportive evidence.

PURPOSE

This study aimed to compare the immediate and short-term effects of emphasizing scapulothoracic joint rehabilitation in addition to conventional physiotherapy on pain, range of motion (ROM), function, quality of life, and treatment effectiveness in patients after shoulder arthroscopic rotator cuff tendon repair (ARCR).

STUDY DESIGN

Two arms, parallel-group, randomized controlled trial, with concealed allocation METHODS: This parallel-group randomized controlled trial, with concealed allocation, was conducted in a clinic setting on 28 participants aged 30-75 years, exhibiting progressive degenerative full-thickness tears of rotator cuff muscles and undergoing ARCR, provided the tear size was small or medium. Participants were randomly allocated to receive 21 sessions of conventional rehabilitation (n = 14) or comprehensive rehabilitation (with a focus on scapula training; n = 14) in 12 weeks (reporting of intervention complied with Consensus on Exercise Reporting Template (CERT) and Template for Intervention Description and Replication (TIDieR) Guideline). Pain (as primary outcome), ROM, functional disability, quality of life, and treatment effectiveness were assessed both pre- and post-intervention, along with a 3-month follow-up. Participants, assessors, and statistician were blinded to group assignment. For the reporting of the RCT, the Consolidated Standards of Reporting Trials (CONSORT) has been used.

RESULTS

Trial was completed with 28 participants and no dropouts. The analysis of variance revealed statistically significant group-by-time interaction (p < 0.05) for all outcome measures except for active ROMs (p > 0.05). Multiple comparison analysis showed statistically significant between-group differences (p < 0.05) at 3-month follow-up with large effect size (>0.8 Hedges' g) for all outcomes (mean differences: visual analog scale: 1.3, American Shoulder and Elbow Surgeons: -17.3, Shoulder Pain and Disability Index: 17.6, Western Ontario Rotator Cuff: -19.5, QuickDASH: 17.8), except for extension ROM (passive ROM: confidence interval = -25.4 to 0.56; active ROM: confidence interval = -20.0 to 6.0). The differences in American Shoulder and Elbow Surgeons and Western Ontario Rotator Cuff were also clinically significant based on their minimally clinical important difference cutoff points. For the Global Rating of Change scale, more participants stated "much improved" in the comprehensive group than in the conventional. No adverse effects were reported.

CONCLUSIONS

Comprehensive rehabilitation, compared to conventional physiotherapy, has shown a statistically and clinically significant difference in improving pain, ROM, functional disability, quality of life, and treatment effectiveness in patients after ARCR.

Variation of muscle recruitment during exercises performed below horizontal arm elevation that target the lower trapezius: A repeated measures cross-sectional study on asymptomatic individuals

The gold standard exercise for recruitment of the lower trapezius is the Y prone exercise which is performed above 90° of shoulder elevation. However, clinicians often prescribe exercises that avoid high elevation postures during early stages of rehabilitation. Comparatively little data exists on relative muscle recruitment during lower arm elevation exercises. This study examined the EMG activity of four shoulder girdle muscles during four exercises accomplished below 90° of shoulder elevation and compared them to the Y prone while considering sex effects. Variance across exercises of the ratio between upper trapezius and lower trapezius was also explored. 32 healthy participants completed standardized muscle-specific MVCs and two repetitions of each exercise. The side lying external rotation and the wall slide exercises produced the highest peak EMG for the lower trapezius, both 33 and 29% lower than the Y Prone. For the upper trapezius to lower trapezius ratio, the side lying external rotation elicited the lowest value, followed by the Y prone and wall slide (53 and 59% respectively higher). Sex influenced some EMG values, typically interacting with exercise type. Thus, side lying external rotation and the wall slide are recommended for targeting the lower trapezius muscle during early rehabilitation.

Immediate Effects of the Reverse Plank Exercise on Muscle Thickness and Postural Angle in Individuals with the Forward Shoulder Posture

The forward shoulder posture (FSP) results from shoulders being pulled forward by shortened anterior shoulder girdle muscles. The objective of this study was to investigate the short-term effectiveness of the reverse plank exercise on parascapular muscle thickness and forward shoulder angle (FSA) in patients with FSP. Participants were divided into the FSP and non-FSP (NFSP) groups based on the observed angle between the horizontal line of the C7 spinous process and the acromion process. All participants performed a total of five sets of reverse plank exercises at 30 s per set. FSA and muscle thickness of the pectoralis major (PM), serratus anterior (SA), upper trapezius (UT), and lower trapezius (LT) were measured before and after the reverse plank exercise. The muscle thicknesses of the SA and LT, and the FSA, were significantly increased after exercise in the FSP group (p < 0.05). Muscle thickness of the PM and UT significantly decreased after the exercise. In the NFSP group, muscle thickness of the LT was significantly increased, and muscle thickness of the PM and UT were significantly reduced after exercise (p < 0.05). Upon using between-group analysis, there were significant differences between the FSA, SA, UT, and LT groups (p < 0.05). The reverse plank exercise has the short-term benefit of correcting and preventing FSP by increasing SA and LT thickness while decreasing PM and UT thickness. We believe that the reverse plank exercise significantly improved the ability to prevent FSP in FSP-related muscles and was beneficial in achieving optimal postural alignment.

Intra-rater reliability of goniometry to measure scapular protraction and retraction

STUDY DESIGN

Observational, descriptive design.

BACKGROUND

Despite scapular mobility being essential for the completion of activities of daily living (ADLs), there is currently no established, a reliable goniometric technique to measure scapular protraction and retraction. A proposed method has shown clinically significant inter-rater reliability for a goniometric technique for these measurements.

PURPOSE

This observational descriptive study examined the intra-rater reliability of a goniometric technique to assess scapular protraction and retraction among a sample of healthy adults.

METHODS

An occupational therapist who is a certified hand therapist (CHT) and an occupational therapy student used goniometry to measure the neutral (resting), protracted, and retracted positions of the right and left scapula for a sample of healthy young adults (n = 54; a total of 108 data points for each measurement). These measurements were compared to analyze intra-rater and inter-rater reliability.

RESULTS

For measurements of the scapula in neutral, protraction, and retraction, the standard error of measure (SEM) for repeat measures by the expert and novice raters was < 4.5° and < 3.9° respectively and ICC values ranged from poor to moderate (0.37-0.63). The SEM for measures between evaluators was < 5.0° and the ICC was poor (0.16-0.35). Minimum detectable change (MDC) values as a percentage of the mean (% MDC) ranged between 15.9 and 43.7% for intra-rater reliability and 21.9-52.8% for inter-rater reliability.

DISCUSSION

The results of the study were mixed; variance of less than 5° for repeat measures by the same rater and measures between raters suggest clinically acceptable reliability. However, variance as a proportion of available motion (%MDC) demonstrates a broader range both above and below the threshold of 30% suggested for rehabilitation assessments.

CONCLUSION

There are few efficient, reliable techniques to measure scapular mobility in clinical practice. The absolute reliability of goniometry to measure scapular protraction and retraction is similar to measurements of other joints. However, additional research and possible refinement of the technique is recommended to further address relative reliability and validity.

Infraspinatus Muscle Fiber Moment Arms During Abduction: A Biomechanical Comparison of Values for Intact Rotator Cuff, Supraspinatus Tear, Superior Capsular Reconstruction, and Reverse Total Shoulder Arthroplasty

Background:

Lines of action of the superior, middle, and inferior infraspinatus muscle fibers work together to produce moment arms that change throughout abduction in an intact shoulder, after a supraspinatus tear, and after superior capsular reconstruction (SCR) and reverse total shoulder arthroplasty (rTSA).

Purpose:

To use moment arm values to indicate the efficacy of SCR and rTSA to restore infraspinatus function during shoulder abduction.

Study Design:

Descriptive laboratory study.

Methods:

A total of 5 human cadaveric shoulders placed in a testing apparatus were each actively abducted (0°-90°) under the following 4 conditions: intact, complete supraspinatus tear, SCR, and rTSA. The 3-dimensional coordinates of points were tracked along the origin and insertion of the superior, middle, and inferior infraspinatus fibers during abduction. Moment arm values were calculated using the origin-insertion method to determine abduction contribution of infraspinatus fiber sections. Analysis of variance and post hoc Tukey testing were used to compare differences in moment arms between the 4 conditions and between fiber sections.

Results:

In the intact condition, the superior infraspinatus fibers had an abduction moment that decreased with elevation until shifting to adduction. Conversely, the middle and inferior fibers had an adduction moment that turned to abduction (mean moment arm values from 0° to 90°: inferior, from –5.9 to 19.4 mm; middle, from –4.7 to 15.9 mm; superior, from 5.6 to –5.1 mm; P < .05). After a supraspinatus tear, superior fibers lacked any torque, and inferior and middle fibers lost adduction potential (inferior, from 4.8 to 14.0 mm; middle, from –0.2 to 9.6 mm; superior, from 1.0 to 0.7 mm; P < .05). SCR restored the initial superior fiber abduction moment (5.6 mm at 0°; P < .05); middle and inferior fibers had some restoration but were weaker than intact fibers. Loss of abduction moment in all fibers was seen with rTSA (inferior, from –9.6 to –1.6 mm; middle, from –10.5 to –3.6 mm; superior, from –1.7 to –4.6 mm; P < .05).

Conclusion:

Infraspinatus fiber groups had different and inverse moment arms during scapular plane elevation. SCR most closely resembled the intact shoulder, whereas rTSA transformed the infraspinatus into an adductor.

Clinical Relevance:

These results support the efficacy of SCR at restoring biomechanical muscle function and suggest that the changes in moment arms for each fiber group be considered when choosing treatment modalities and rehabilitation protocols after rotator cuff tear.

Diaphragmatic Mobility and Chest Expansion in Patients with Scapulocostal Syndrome: A Cross-Sectional Study

Scapulocostal syndrome (SCS) is a subset of myofascial pain syndrome affecting the posterior shoulder and upper back area. Some of the affected muscles are attached to the rib cage, which may affect diaphragmatic mobility and chest expansion. The purpose of this study was to investigate the characteristics of diaphragmatic mobility and chest expansion in patients with SCS. Twenty-nine patients with SCS and twenty-nine healthy participants of a similar age, gender, weight, and height were included in the study. All participants were evaluated for diaphragmatic mobility (DM) by real-time ultrasound (RTUS) and for chest expansion (CE) using a cloth tape measure. An independent t-test was used to compare the outcome variables between groups. The DM value in the SCS group was 46.24 ± 7.26 mm, whereas in the healthy group it was 54.18 ± 9.74 mm. The DM value was lower in the SCS group compared to in healthy participants (p < 0.05). Chest expansion at the axilla, the fourth intercostal space (4th ICS), and the xiphoid level in the SCS group was 7.26 ± 1.13, 6.83 ± 0.94, and 6.86 ± 1.25, respectively, while chest expansion at the axilla, 4th ICS, and xiphoid level in the healthy group was 7.92 ± 1.39, 7.54 ± 1.43, and 8.13 ± 1.32, respectively. Chest expansion at the 4th ICS and the xiphoid level in the SCS group was significantly lower than in the healthy group (p < 0.05). Patients with SCS presented a decrease in diaphragmatic mobility and chest expansion. Therefore, SCS treatment programs ought to add breathing exercises to improve lung expansion.

Relationship between scapular control during isometric shoulder flexion and scapular motion during baseball pitching: a cross-sectional study

Background

A baseball pitcher with decreased scapular control may not be able to achieve suitable scapular motion at maximum shoulder external rotation (MER) of baseball pitching during the pitching action. It is common clinically to compare scapular control of the throwing and non-throwing arms to detect side-to-side differences. However, it remains unclear whether scapular control is different between the throwing and non-throwing arms. Moreover, no data exist on the relationship between scapular control and scapular motion at MER of pitching. Primarily, this study aimed to compare scapular control during isometric shoulder flexion between the throwing and non-throwing arms. Secondly, this study aimed to investigate the relationship between scapular control during isometric shoulder flexion and scapular motion at MER of pitching.

Methods

Fifteen healthy collegiate baseball pitchers (age, 20.2 ± 1.9 years; height, 1.76 ± 0.05 m; body mass, 73.3 ± 6.7 kg) were recruited. An optical motion tracking system was used to assess scapular motion. Scapular control was defined as the amount of change in the scapular internal rotation angle, downward rotation angle, and anterior tilt angle during isometric shoulder flexion. We assessed scapular position at MER of pitching.

Results

No significant differences were detected for any of the scapular angles during isometric shoulder flexion between the throwing and non-throwing arms. The amount of change in the scapular internal rotation angle, scapular downward rotation angle, and scapular anterior tilt angle during isometric shoulder flexion had a significant relationship with the scapular downward rotation angle at MER.

Conclusions

No side-to-side difference was noted in scapular control during isometric shoulder flexion in healthy collegiate baseball pitchers at the group level. Further studies are required to understand the side-to-side differences at the individual level. Additionally, there was a relationship between scapular control during isometric shoulder flexion and scapular position at MER. These findings suggest that clinicians may consider using isometric shoulder flexion to assess scapular control in baseball pitchers.

Effects of a Novel Rotator Cuff Rehabilitation Device on Shoulder Strength and Function

ABSTRACT

Savitzky, JA, Abrams, LR, Galluzzo, NA, Ostrow, SP, Protosow, TJ, Liu, SA, Handrakis, JP, and Friel, K. Effects of a novel rotator cuff rehabilitation device on shoulder strength and function. J Strength Cond Res 35(12): 3355-3363, 2021-The glenohumeral joint, a multiaxial ball and socket joint, has inherent instability counterbalanced by the muscular stability of the rotator cuff (RC) and connective tissue. Exercise has been shown to alleviate pain and disability arising from degenerative changes of the RC due to overuse, trauma, or poor posture. This study compared the training effects of ShoulderSphere (SS), an innovative device that uses resistance to centrifugal force, to TheraBand (TB), a traditional device that uses resistance to elasticity. Thirty-five healthy male and female adults (24.2 ± 2.4 years) were randomized into 3 groups: SS, TB, and control. Five outcomes were assessed before and after the twice-weekly, 6-week intervention phase: strength (shoulder flexion [Fx], extension [Ext], external rotation [ER], and internal rotation [IR]), proprioception (6 positions), posterior shoulder endurance (ShEnd), stability (Upper Quarter Y-Balance Test [YBal] (superolateral [YBalSup], medial [YBalMed], and inferolateral [YBalInf]), and power (seated shot put [ShtPt]). Data were analyzed using a 3 (group: SS, TB, and control) × 2 (time: pre and post) generalized estimating equation. Analyses demonstrated a main effect of time for all strength motions (p < 0.01): YBalInf (p < 0.0001), ShtPt (p < 0.05), and ShEnd (p < 0.0001) but no interaction effects of group × time. There were no main or interaction effects for proprioception. Both SS and TB groups had significant within-group increases in Ext, IR, YBalInf, and ShEnd. Only the SS group had significant increases in ER, Fx, and ShtPt. ShoulderSphere demonstrated comparable conditioning effects with TB and may afford additional strength gains in Fx and ER, and power. ShoulderSphere should be considered a viable alternative in RC conditioning.

The effects of muscle fatigue on scapulothoracic joint position sense and neuromuscular performance

BACKGROUND

Fatigue of the scapular musculature might affect the sensorimotor system and neuromuscular control and therefore impair the dynamic alignment of the scapula. The purpose of this study was to investigate the effects of scapular muscle fatigue on joint position sense and the neuromuscular performance of the scapulothoracic joint.

METHODS

Thirty healthy subjects were recruited. The joint position sense (measured as reposition errors during the scapular elevation and protraction task) of the scapulothoracic joint and scapular kinematics and muscle activation (% of maximum voluntary isometric contraction) during scaption, shoulder elevation in the scapular plane, before and after the fatigue task (modified push-up) were measured. The repeated measures analysis of variance (ANOVA) was used to assess the effects of fatigue on scapular reposition error and neuromuscular control.

RESULTS

Although joint reposition sense did not change after fatigue, muscle activation of the serratus anterior increased significantly (18.5%-26.3%, p = 0.006, elevation task; 15.2%-27.4%, p = 0.037, protraction task). At 120° scaption, the scapula showed a decreased posterior tilt (13.8°-10.3°, p < 0.001), increased protraction (10.2°-13.3°, p = 0.004) and lateral rotation (52.8°-54.4°, p = 0.005). Muscle activation of the serratus anterior increased (65.9%-84.6%, p = 0.002) during 90°-120°scaption.

CONCLUSION

Scapular muscle fatigue did not alter the scapulothoracic joint position sense, but increased serratus anterior activation and resulted in a more anteriorly tilted, protracted, and laterally rotated scapula during scaption. Whether or not these fatigue-related changes are linked to the development of shoulder problems needs to be investigated further.

Mapping of common rib fracture patterns and the subscapular flail chest associated with operative scapula fractures

BACKGROUND

Rib fractures occur in approximately 10% of trauma patients and are associated with more than 50% of patients with scapula fractures. This study investigates the location and patterns of rib fractures and flail chest occurring in patients with operatively treated scapula fractures. Novel frequency mapping techniques of rib fracture patterns in patients who also injure the closely associated scapula can yield insight into surgical approaches and fixation strategies for complex, multiple injuries patients. We hypothesize that rib fractures have locations of common occurrence when presenting with concomitant scapula fracture that requires operative treatment.

METHODS

Patients with one or more rib fractures and a chest computed tomography scan between 2004 and 2018 were identified from a registry of patients having operatively treated scapula fractures. Unfurled rib images were created using Syngo-CT Bone Reading software (Siemens Inc., Munich, Germany). Rib fracture and flail segment locations were marked and measured for standardized placement on a two-dimensional chest wall template. Location and frequency were then used to create a gradient heat map.

RESULTS

A total of 1,062 fractures on 686 ribs were identified in 86 operatively treated scapula fracture patients. The mean ± SD number of ribs fractured per patient was 8.0 ± 4.1 and included a mean ± SD of 12.3 ± 7.2 total fractures. Rib fractures ipsilateral to the scapula fracture occurred in 96.5% of patients. The most common fracture and flail segment location was ipsilateral and subscapular; 51.4% of rib fractures and 95.7% of flail segments involved ribs 3 to 6.

CONCLUSION

Patients indicated for operative treatment of scapula fractures have a substantial number of rib fractures that tend to most commonly occur posteriorly on the rib cage. There is a pattern of subscapular rib fractures and flail chest adjacent to the thick bony borders of the scapula. This study enables clinicians to better evaluate and diagnose scapular fracture patients with concomitant rib fractures.

LEVEL OF EVIDENCE

Diagnostic test, level IV.

Comparison of In Vivo Three-Dimensional Glenohumeral Positions and Scapular Kinematics between Young and Older Male Groups

Background

Many researchers have questioned whether shoulder kinematics such as the glenohumeral position and scapular kinematics would be different in different age groups. However, studies comparing shoulder kinematics between different age groups have been rare. The aim of this study was to analyze and compare the three-dimensional (3D) glenohumeral position, scapular kinematics, and scapulohumeral rhythm (SHR) during scapular plane arm abduction between a normal young male group and a normal older male group.

Methods

Twenty normal men (10 young and 10 older) were enrolled in this controlled laboratory study. Fluoroscopic images were obtained using a single plane X-ray system. Bilateral computed tomography scans were taken to create a 3D model. A 3D-2D registration technique was used to determine the 3D position and orientation of the bones of the shoulder.

Results

During scapular plane arm abduction, there were significant differences in scapular kinematics between the groups. The older male group showed more upward rotation, posterior tilt, and external rotation than the young male group. On the other hand, the glenohumeral position such as superior inferior translation, anterior posterior translation, and external rotation of the humeral head did not show significant difference between the groups. The mean value of SHR for the overall arm elevation range from start to maximum elevation angle for the older group and young group was 2.298 ± 0.964 and 2.622 ± 0.931, respectively, showing a significant difference between the two groups (p = 0.035).

Conclusions

Scapular kinematics and SHR were significantly different between the older male group and the young male group. Our study could provide reference values of shoulder kinematics for older men aged 55–65 years.

Feedback improves the scapular-focused treatment effects in patients with shoulder impingement syndrome

PURPOSE

This study aimed to evaluate the effects of scapular-focused treatment with (SFTF) and without (SFT) feedback on pain, function, and scapular kinematics in patients with Shoulder Impingement Syndrome (SIS).

METHODS

Seventy-five males and females with SIS were randomly assigned into SFTF (n = 25), SFT (n = 25) and control (n = 25) groups. The primary outcome was pain, assessed by Visual Analog Scale (VAS). The secondary outcomes were function and scapular kinematics, assessed by DASH Questionnaire and a 3-D motion capture, respectively. All outcomes were measured at the baseline and after the 8-week interventions.

RESULTS

A post hoc analysis performed to show significant differences between groups after the 8-week interventions. For pain, there were significant differences between SFTF vs. SFT (ES (95% CI) = - 0.3(- 0.4 to - 0.1); P = 0.04), SFTF vs. control (ES (95% CI) = 1.3(0.7-1.9); P = 0.01). For DASH, also, there were significant differences between SFTF vs. SFT (ES (95% CI) = 1.8(1.1-2.4); P = 0.03), SFTF vs. control (ES (95% CI) = 4.4(3.3-5.4); P = 0.01), and SFT vs. control (ES (95% CI) = 2.6(1.8-3.4); P = 0.01). For scapular internal rotation (the sagittal or scapular planes), scapular upward rotation, and the scapular tilt, however, there were no differences between SFTF vs. SFT.

CONCLUSION

Based on the study results, a rehabilitation program integrated with verbal feedbacks is effective to relieve pain, and improve function and scapular kinematics in patients with SIS. Adding feedback to an exercise therapy could clinically enhance outcomes in patients with SIS.

LEVEL OF EVIDENCE

Level II.

TRIAL REGISTRATION

This study was prospectively registered at UMIN-CTR website, and the unique trail number is UMIN000036399.

Evaluation of rotator cuff abduction moment arms for superior capsular reconstruction and reverse total shoulder arthroplasty

PURPOSE

The rotator cuff (RC) muscles contribute to dynamic stability and rotational actions of the glenohumeral joint. Moment arm can be used to demonstrate the potential work a muscle contributes to a musculoskeletal joint rotation. This study aimed to understand the moment arm contributions of the RC muscles and explore changes following a complete supraspinatus tear treated with either superior capsular reconstruction (SCR) or reverse total shoulder arthroplasty (rTSA).

METHODS

Five fresh-frozen cadaveric specimens were prepared and mounted in an apparatus where each intact RC muscle was held in tension with a line of action toward its origin on the scapula. Mean moment arms for each muscle were determined experimentally based on Optotrak data collected during cadaveric shoulder arm abduction.

RESULTS

Using ANOVA testing, our analysis demonstrated significant differences (p < 0.001) in infraspinatus and teres minor moment arms after rTSA compared to the intact shoulder model. After SCR, significant differences (p < 0.001) were seen in teres minor, with these differences being statistically similar to the changes seen in teres minor after rTSA. Subscapularis showed no significant difference in moment arm values between the models (p = 0.148).

CONCLUSION

Our results illustrate that mean moment arms were preserved in the RC muscles after complete supraspinatus tear. This study also shows evidence that subscapularis function may be maintained after SCR or rTSA. After SCR, infraspinatus may maintain similar abduction ability compared to the anatomical shoulder, while teres minor ability may increase. Infraspinatus may have decreased abduction ability after rTSA while teres minor may have increased ability.

A novel multi-study intervention investigating the short and long term effects of a posture bra on whole body and breast kinematics

BACKGROUND

Poor standing posture has been reported in women with larger breasts, increasing the risk of back pain. Whilst breast reduction surgery can improve posture, conservative measures such as special bras may offer short or long-term relief of symptoms without surgical intervention.

RESEARCH QUESTION

This study aimed to utilise a multi-study intervention to investigate the short and long-term kinematic effects of wearing a posture bra.

METHODS

Study one utilised biomechanics and physiotherapy expertise to modify the design of a prototype bra to improve posture and breast kinematics; resulting in a second-generation posture bra. To test this bra, 24 females were randomly assigned to control and intervention groups. The control group wore their everyday bra; the intervention group wore the generation 2 posture bra in place of their everyday bra for three months. Pre and post intervention, posture (spine curvature, scapula position, whole body alignment) and breast kinematics were assessed during sitting, standing and walking. Short-term effects of the posture bra were compared to an everyday bra and no bra (study two), whilst the long-term effects were compared using the no bra condition (study three).

RESULTS

Biomechanical intervention improved posture and breast kinematics in a prototype posture bra resulting in a second-generation prototype. Pre-intervention, the generation 2 posture bra significantly improved scapula retraction by 6° during both sitting and standing, but also increased deviation of whole body alignment compared to everyday bra and no bra conditions. During walking the posture bra reduced breast motion by 17 % compared to the everyday bra. Following the three-month wearer intervention, scapula depression significantly improved in the intervention group.

SIGNIFICANCE

A biomechanically informed posture bra was able to effectively support the breasts and improve scapula position without compromising spinal curvature, reducing the risk of musculoskeletal pain associated with poor posture.

Trapezius and serratus anterior muscle strength in violinists with unilateral neck pain

BACKGROUND

Weakness of the trapezius and serratus anterior (SA) muscle may be a risk factor for unilateral neck pain.

OBJECTIVE

This study examined the trapezius (upper, middle, and lower) and SA muscle strength ipsilateral and contralateral to the painful side in violinists with unilateral neck pain.

METHOD

Twenty-six female violinists with unilateral neck pain participated in this study. Participants reported the pain intensity and duration and completed the Neck Disability Index (NDI). The strengths of the upper (UT), middle (MT), and lower (LT) trapezius and SA muscles were measured using a handheld dynamometer. Paired t-test was used to compare the strength of the muscles between ipsilateral and contralateral to the painful side within subjects. The relationship between pain intensity, pain duration, and neck disability and strength deficit of the muscle was demonstrated by Pearson's correlation and Spearman's rank correlation.

RESULTS

The strengths of the UT, MT, LT, and SA muscles were significantly decreased on the painful side compared with the contralateral side (P< 0.05). Except for correlations between pain intensity and percent strength deficit of the UT and between pain duration and percent strength deficit of the MT (P< 0.05), there were no significant associations between pain intensity, pain duration, or NDI and the percent strength deficit of the UT, MT, LT and SA muscles (P> 0.05).

CONCLUSIONS

These results suggest that decreased UT, MT, LT, and SA muscle strength on the side of the pain should be considered in the rehabilitation of violinists with unilateral neck pain.

The Effectiveness of an Upper Extremity Neuromuscular Training Program on the Shoulder Function of Military Members With a Rotator Cuff Tendinopathy: A Pilot Randomized Controlled Trial

INTRODUCTION

Shoulder pain, a leading reason to consult a physician or physiotherapist, continues to be a challenge to rehabilitate, particularly with a military population. A rotator cuff (RC) tendinopathy, the most important source of shoulder pain, is one of the leading reasons for sick leave or a discharge from active military service. Research encourages the use of exercise prescription for the management of a RC tendinopathy, however the ideal method of delivery (group setting versus one-on-one) remains uncertain. The purpose of this single-blind (evaluator) pilot randomized clinical trial was to compare two 6-week rehabilitation programs, a newly developed group-supervised neuromuscular training program and usual one-on-one physiotherapy care, on the pain and symptoms of Canadian soldiers affected by a RC tendinopathy.

MATERIALS AND METHODS

Thirty-one soldiers with the Canadian Armed Forces were randomly assigned to (1) a group-supervised neuromuscular training program (UPEx-NTP) or; (2) one-on-one usual physiotherapy care (UPC). The primary outcome was the Disability of Arm, Hand and Shoulder (DASH) questionnaire. Secondary outcomes included the Western Ontario Rotator Cuff (WORC) Index, pain levels at rest, and maximum isometric voluntary contractions (MIVC) of the abductors and external (lateral) rotators of the affected shoulder. Both were assessed at baseline (T0), 6 (T6) and 12 (T12) weeks. Analysis included two-way repeated measures of variance for intention-to-treat (ITT) and per-protocol analyses.

RESULTS

Eighty military members with a RC tendinopathy were contacted, resulting in 31 participants who were randomized for their active intervention, in the UPEx-NTP or UPC, respectively. No significant group (p ≥ 0.16) or group × time interactions (p ≥ 0.11) were found for either ITT or per-protocol analyses. A statistically significant time effect (p < 0.001) was established for the DASH and WORC, showing that both groups improved over time.

CONCLUSIONS

Our preliminary data demonstrates that both rehabilitation approaches, grounded in active exercises, were not statistically different from each other, and derived similar benefits over time for a military population. This suggests that a group intervention for a RC tendinopathy has potential to be just as effective as a one-on-one approach for a military population, an interesting avenue for an active working population. Larger sample sizes and further investigation are warranted regarding the cost and clinical resource benefits of a supervised group approach.

Posterior shoulder tightness can be a risk factor of scapular malposition: a cadaveric biomechanical study

BACKGROUND

Scapular malposition and posterior shoulder tightness are key pathologic processes in the shoulder of throwing athletes. The objective of this study was to investigate the effects of posterior capsule tightness, posterior rotator cuff muscle tightness, or both on scapular position.

METHODS

Ten shoulders from 5 fresh frozen cadaveric male torsos were tested in maximum internal, neutral, and maximum external shoulder rotations at 0°, 45°, and 90° of shoulder abduction. Scapular rotation-namely, upward and downward rotation, internal and external rotation, and anterior and posterior tilt-and the scapula-spine distance were measured by using a MicroScribe digitizer (Revware, Raleigh, NC, USA). Each shoulder underwent 4 experimental stages: intact; isolated posterior rotator cuff muscle (infraspinatus and teres minor) tightness; both posterior rotator cuff muscle and capsule tightness; and isolated posterior capsule tightness.

RESULTS

Posterior muscle tightness significantly decreased upward rotation (P< .05) only in maximum shoulder internal rotation at 45° or 90° of shoulder abduction, whereas posterior capsule tightness did not affect upward rotation (P= .09 to .96). Posterior capsule tightness significantly increased scapular internal rotation (P< .01), but posterior muscle tightness did not change scapular internal rotation (P= .62 to .89). Posterior capsule tightness significantly increased both the superior and inferior scapula-spine distance (ie, caused scapular protraction) in maximum shoulder external rotation at 90° of abduction (P< .01).

CONCLUSION

Posterior shoulder tightness resulted in scapular malposition. However, the muscular and capsular components of that tightness affected the scapular position differently. For the treatment of scapula malposition, stretching of the posterior shoulder capsule and muscles is recommended.

Is Scapular Stabilization Exercise Effective for Managing Nonspecific Chronic Neck Pain?: A Systematic Review

Scapular stabilization is thought to have an important role in improving pain and dysfunction around the neck and shoulders, but evidence of this is lacking. We aim to systematically review the effect of a scapular stabilization exercise (SSE) on pain and dysfunction in patients with nonspecific chronic neck pain (NP). We searched the PubMed, EMBASE, CINAHL, and Cochrane Library databases using the terms (NP [MeSH] OR NP OR cervical pain OR neck ache OR cervicalgia) AND (scapular exercise OR periscapular exercise OR SSEs). We included suitable studies that met the study's inclusion criteria. Among the 227 studies identified by our search strategy, a total of four (three randomized controlled studies and one prospective study) met the inclusion criteria. The SSE was intense. It included three sets of 10 repetitions. In most of the studies, the exercises were conducted 3 times per week. Most studies reported that the SSE improved pain and dysfunction in patients with nonspecific chronic NP; however, the reviewed articles did not use the same variables for measurement. Additionally, the sample size was small. Although several studies show that SSE might improve NP and dysfunction, the effects of SSE on pain and dysfunction in the neck region remain unclear because the number of studies was small. Further high-quality studies are necessary to identify the detailed effects of SSE in patients with NP.

Scapula Dyskinesis: A Review of Current Concepts and Evaluation of Assessment Tools

Scapula dyskinesis is prevalent in athletes conducting forceful overhead movements. This review summarizes our current understanding of the condition and evaluates the different options for assessing dyskinesis. Current methods for assessing scapula dyskinesis involve clinical observations, three-dimensional kinematics and three-dimensional wing computer tomography. Clinical observation is the most pragmatic method for assessing dyskinesis yielding inter-rater agreement of 79% and sensitivity of 76%. Similar sensitivities have been recorded using three-dimensional kinematics. Three-dimensional wing computer tomography has yielded a near-perfect interclass correlation coefficient of 0.972 when used to assess dyskinesis. Three-dimensional wing computer tomography, given its expense, low availability, and levels of irradiation, should be reserved for high-performance athletes where detailed assessments need to be made to aid rehabilitation. Observational assessments should remain the main modality used for general assessment.

Scapular kinematic and shoulder muscle activity alterations after serratus anterior muscle fatigue

BACKGROUND

Although the serratus anterior muscle has an important role in scapular movement, no study to date has investigated the effect of serratus anterior fatigue on scapular kinematics and shoulder muscle activity. The purpose of this study was to clarify the effect of serratus anterior fatigue on scapular movement and shoulder muscle activity.

METHODS

The study participants were 16 healthy men. Electrical muscle stimulation was used to fatigue the serratus anterior muscle. Shoulder muscle strength and endurance, scapular movement, and muscle activity were measured before and after the fatigue task. The muscle activity of the serratus anterior, upper and lower trapezius, anterior and middle deltoid, and infraspinatus muscles was recorded, and the median power frequency of these muscles was calculated to examine the degree of muscle fatigue.

RESULTS

The muscle endurance and median power frequency of the serratus anterior muscle decreased after the fatigue tasks, whereas the muscle activities of the serratus anterior, upper trapezius, and infraspinatus muscles increased. External rotation of the scapula at the shoulder elevated position increased after the fatigue task.

CONCLUSION

Selective serratus anterior fatigue due to electric muscle stimulation decreased the serratus anterior endurance at the flexed shoulder position. Furthermore, the muscle activities of the serratus anterior, upper trapezius, and infraspinatus increased and the scapular external rotation was greater after serratus anterior fatigue. These results suggest that the rotator cuff and scapular muscle compensated to avoid the increase in internal rotation of the scapula caused by the dysfunction of the serratus anterior muscle.

Immediate effects of scapular stabilizing exercise in chronic stroke patient with winging and elevated scapula: a case study

[Purpose] The purpose of this study was to investigate the effect of scapular stabilizing exercise in a stroke patient with winging and elevated scapula. [Subject and Methods] The subject was a 46-year-old female with a history of stroke. She had right side hemiplegia with winging and elevated scapula on the right side, and had compensatory motions of the neck and shoulder when using the paretic upper extremity. The subject participated in scapular stabilizing exercises for four days. This exercise program consisted of scapular protraction-retraction in an upright seated position. Scapular position was measured as distance between scapular medial border and thoracic vertebrae 3, 4. Upper extremity function was measured as time required for lifting and lowering a cup with the affected arm. [Results] After intervention, distance between scapular medial border and spinouse process of T3, 4 decreased. Time required for lifting and lowering a cup with the affected arm decreased. Compensatory motions of the neck and shoulder joint decreased. [Conclusion] Despite the short period, scapular stabilizing exercises had a positive effect on scapular position and upper extremity function.

POSTURAL ALTERATIONS IN PATIENTS WITH SUBACROMIAL IMPINGEMENT SYNDROME

Background

An aberrant upper body posture has been proposed as one of the etiological factors contributing to the development of subacromial impingement syndrome (SAIS). Clinicians have translated this supposition into assessment and rehabilitation programs despite insufficient and conflicting evidence to support this approach.

Purpose

The purpose of this study was to compare several postural variables between the SAIS patients and asymptomatic healthy controls.

Study Design

Case-Control Study.

Methods

A total of 75 participants including 39 patients (20 females; 19 males) and 36 healthy controls (15 females; 21 males) participated in the study. Study evaluated several postural variables including forward head posture (FHP), forward shoulder posture (FSP), thoracic kyphosis index (TKI), scapular index (SI), normalized scapular protraction (NSP), and the lateral scapular slide test (LSST). The variables were compared between patient and control groups according to sex.

Results

Significant differences were observed in the female patients compared to asymptomatic controls for the FHP (49.38 + 9.6o vs 55.5o+8.38, p=0.03), FSP (45.58 + 10.1o vs 53.68 + 7.08, p=0.02), and LSST in third position (10.2 + 2.1cm vs 11.5 + 0.7cm, p=0.01). Male patients showed a significant difference only in the FSP compared to controls (61.9o+9.4o vs 49.78 + 9.28, p<0.001).

Conclusions

While inadequate data on the relationship between dysfunctional posture and SAIS has led to broad variations in current rehabilitation strategies, the results of the present study revealed different patterns of postural aberrations in female and male patients with SAIS. This clarifies the need to develop individualized or sex-specific approaches for assessing posture in men and women with SAIS and rehabilitation programs based on the assessment results.

Level of Evidence

3b.

Negative Influence of Motor Impairments on Upper Limb Movement Patterns in Children with Unilateral Cerebral Palsy. A Statistical Parametric Mapping Study

Upper limb three-dimensional movement analysis (UL-3DMA) offers a reliable and valid tool to evaluate movement patterns in children with unilateral cerebral palsy (uCP). However, it remains unknown to what extent the underlying motor impairments explain deviant movement patterns. Such understanding is key to develop efficient rehabilitation programs. Although UL-3DMA has been shown to be a useful tool to assess movement patterns, it results in a multitude of data, challenging the clinical interpretation and consequently its implementation. UL-3DMA reports are often reduced to summary metrics, such as average or peak values per joint. However, these metrics do not take into account the continuous nature of the data or the interdependency between UL joints, and do not provide phase-specific information of the movement pattern. Moreover, summary metrics may not be sensitive enough to estimate the impact of motor impairments. Recently, Statistical Parametric Mapping (SPM) was proposed to overcome these problems. We collected UL-3DMA of 60 children with uCP and 60 typically developing children during eight functional tasks and evaluated the impact of spasticity and muscle weakness on UL movement patterns. SPM vector field analysis was used to analyze movement patterns at the level of five joints (wrist, elbow, shoulder, scapula, and trunk). Children with uCP showed deviant movement patterns in all joints during a large percentage of the movement cycle. Spasticity and muscle weakness negatively impacted on UL movement patterns during all tasks, which resulted in increased wrist flexion, elbow pronation and flexion, increased shoulder external rotation, decreased shoulder elevation with a preference for movement in the frontal plane and increased trunk internal rotation. Scapular position was altered during movement initiation, although scapular movements were not affected by muscle weakness or spasticity. In conclusion, we identified pathological movement patterns in children with uCP and additionally mapped the negative impact of spasticity and muscle weakness on these movement patterns, providing useful insights that will contribute to treatment planning. Last, we also identified a subset of the most relevant tasks for studying UL movements in children with uCP, which will facilitate the interpretation of UL-3DMA data and undoubtedly contribute to its clinical implementation.

Kinematic Analysis of a Drinking Task in Chronic Hemiparetic Patients Using Features Analysis and Statistical Parametric Mapping

OBJECTIVE

To compare sitting posture and movement strategies between chronic hemiparetic and healthy subjects while performing a drinking task, using statistical parametric mapping (SPM) and feature analysis.

DESIGN

Cross-sectional study.

SETTING

A university physical therapy department.

PARTICIPANTS

Participants (N=26) consisted of chronic hemiparetic (n=13) and healthy individuals (n=13) matched for sex and age.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The drinking task was divided into phases: reaching, transporting the glass to mouth, transporting the glass to table, and returning to initial position. An SPM 2-sample t test was used to compare the entire kinematic waveforms of different joint angles (trunk, scapulothoracic, humerothoracic, elbow). Joint angles at the beginning and end of the motion, movement time, peak velocity timing, trajectory deviation, normalized integrated jerk, and range of motion were extracted from the motion data. Group differences for these parameters were analyzed using independent t tests.

RESULTS

At the static posture and beginning of the reaching phase, patients showed a shoulder position more deviated from the midline and externally rotated with increased scapula protraction, medial rotation, anterior tilting, trunk anterior flexion and inclination to the paretic side. Altered spatiotemporal variables throughout the task were found in all phases, except for the returning phase. Patients returned to a similar posture as the task onset, except for the scapula, which was normalized after the reaching phase.

CONCLUSIONS

Chronic hemiparetic subjects showed more deviations in the proximal joints during seated posture and reaching. However, the scapular movement drew nearer to the healthy individuals' patterns after the first phase, showing an interesting point to consider in rehabilitation programs.

Acute effect of scapular proprioceptive neuromuscular facilitation (PNF) techniques and classic exercises in adhesive capsulitis: a randomized controlled trial

[Purpose] The aim of our study was to compare the initial effects of scapular proprioceptive neuromuscular facilitation techniques and classic exercise interventions with physiotherapy modalities on pain, scapular dyskinesis, range of motion, and function in adhesive capsulitis. [Subjects and Methods] Fifty-three subjects were allocated to 3 groups: scapular proprioceptive neuromuscular facilitation exercies and physiotherapy modalities, classic exercise and physiotherapy modalities, and only physiotherapy modalities. The intervention was applied in a single session. The Visual Analog Scale, Lateral Scapular Slide Test, range of motion and Simple Shoulder Test were evaluated before and just after the one-hour intervention in the same session (all in one session). [Results] All of the groups showed significant differences in shoulder flexion and abduction range of motion and Simple Shoulder Test scores. There were statistically significant differences in Visual Analog Scale scores in the proprioceptive neuromuscular facilitation and control groups, and no treatment method had significant effect on the Lateral Scapular Slide Test results. There were no statistically significant differences between the groups before and after the intervention. [Conclusion] Proprioceptive neuromuscular facilitation, classic exercise, and physiotherapy modalities had immediate effects on adhesive capsulitis in our study. However, there was no additional benefit of exercises in one session over physiotherapy modalities. Also, an effective treatment regimen for shoulder rehabilitation of adhesive capsulitis patients should include scapular exercises.

Scapula Kinematics of Youth Baseball Players

Literature has revealed the importance of quantifying resting scapular posture in overhead athletes as well as quantifying scapular kinematics during dynamic movement. Prior to this project much of the attention in throwing research had been focused on the position of the humerus without description of the positioning of the scapula. Therefore, it was the purpose of this study to present scapular kinematics during pitching in youth baseball players. Twenty-five youth baseball players (age 11.3 + 1.0 years; body height 152.4 + 9.0 cm; body mass 47.5 + 11.3 kg), with no history of injury, participated in the study. Scapular kinematics at the events of maximum humeral external rotation (MER) and maximum humeral internal rotation (MIR) during the pitching motion were assessed three-dimensionally while pitching fastballs for strikes. Results revealed that at the event of MER, the scapula was in a position of retraction, upward rotation and a posterior tilt. While at the event of MIR, the scapula was protracted, upward rotated and tilted anteriorly.

The effects of active scapular protraction on the muscle activation and function of the upper extremity

[Purpose] The purpose of this study was to determine the effects of adjusting the scapula into its ideal position through active scapular protraction on the muscle activation and function of the upper extremity. [Subjects] Twenty female college students aged 19-21 without any physical or functional disability were the subjects of this study. They had no history of injury to their upper extremities or hands. [Methods] After the initial measurements the experimental group was asked to perform active scapular protraction; then, their grip strength and muscle activation were measured again. Every action was maintained for 5 seconds and repeated 3 times. The mean values of the measurements were analyzed. A resting of 1 minute was given between each action. [Results] The results revealed a significant change in the experimental group's grip strength after active scapular protraction had been performed. The surrounding muscles of the scapula, such as the serratus anterior, upper trapezius, flexor carpi ulnaris, flexor carpi radialis and palmaris longus, showed significant changes in muscle activation after active scapular protraction. The muscles of the upper extremity also showed significant changes after active scapular protraction. [Conclusion] The adjustment of scapula into its ideal position through active scapular protraction increased the activations of the muscles surrounding the shoulder joint and improved the function of the upper extremity.

Effect of scapular orientation on shoulder internal impingement in a cadaveric model of the cocking phase of throwing

BACKGROUND

Although deviations in scapular orientation are thought to predispose to shoulder injuries in throwing athletes, the biomechanical mechanism underlying shoulder injuries in throwing athletes with an altered scapular orientation remains unclear.

METHODS

Seven fresh-frozen cadaveric shoulders were evaluated at 90° of abduction, with the humerus externally rotated from 90° to the maximum angle, to simulate the late cocking phase of the throwing motion. Loads were applied to the deltoid, pectoralis major, latissimus dorsi, teres major, and all rotator cuff muscles. Contact pressure in the glenohumeral joint was measured with use of a pressure sensor. The area of internal impingement was calculated on the basis of three-dimensional position data. Glenohumeral contact pressure and the area of impingement were compared between 20°, 30°, and 40° of internal scapular rotation; between 20°, 30°, and 40° of upward scapular rotation; and between 0° and 10° of anterior scapular tilt. Data were analyzed with use of repeated-measures analysis of variance with the Tukey post hoc test.

RESULTS

Contact pressure was at its maximum in the posterior aspect of the glenohumeral joint. The glenohumeral contact pressure and internal impingement area increased with increasing internal scapular rotation. The glenohumeral contact pressure at 40° of internal scapular rotation was significantly (43.4%) greater than that at 20° of internal scapular rotation (p < 0.01), and the impingement area at 40° of internal scapular rotation was significantly (43.1%) greater than that at 20° of internal scapular rotation (p < 0.05). Decreasing upward scapular rotation resulted in an increase in internal impingement area. The internal impingement area at 40° of upward motion was 38.1% less than that at 20° of upward rotation (p < 0.001) and 28.9% less than that at 30° of upward rotation (p < 0.01).

CONCLUSIONS

Increasing internal scapular rotation and decreasing upward scapular rotation significantly increase glenohumeral contact pressure and the area of impingement of the rotator cuff tendon between the greater tuberosity and glenoid during simulated throwing motion.

Three-dimensional upper limb movement characteristics in children with hemiplegic cerebral palsy and typically developing children

The aim of this study was to measure which three-dimensional spatiotemporal and kinematic parameters differentiate upper limb movement characteristics in children with hemiplegic cerebral palsy (HCP) from those in typically developing children (TDC), during various clinically relevant tasks. We used a standardized protocol containing three reach tasks (forwards, upwards, and sideways), two reach-to-grasp tasks (with objects requiring different hand orientations), and three gross motor tasks. Spatiotemporal (movement duration, trajectory straightness, maximum velocity, and timing of maximum velocity), as well as kinematic parameters (discrete angles and waveforms of the trunk, scapula, shoulder, elbow and wrist), were compared between 20 children with HCP (age 10.9 ± 2.9 years) and 20 individually age-matched TDC (age 10.9 ± 3.0 years). Kinematic calculations followed the recommendations from the International Society of Biomechanics. Results showed that children with HCP had longer movement durations, less straight hand trajectories, and lower maximum velocities compared to the TDC. Timing of maximum velocity did not differ between both groups. The movement pathology in children with HCP was highlighted by increased trunk movements and reduced shoulder elevation during reaching and reach-to-grasp. We also measured an increased anterior tilting and protraction of the scapula in children with HCP, although differences were not significant for all tasks. Finally, compared to the TDC, children with HCP used less elbow extension and supination and more wrist flexion to execute all tasks. This study reported distinct 3D upper limb movement characteristics in children with HCP and age-matched TDC, establishing the discriminative ability of the measurement procedure. From a clinical perspective, combining spatiotemporal and kinematic parameters may facilitate the identification of the pathological movement patterns seen in children with HCP and thereby add to a well-targeted upper limb treatment planning.

Minor or occult shoulder instability: an intra-articular pathology presenting with extra-articular subacromial impingement symptoms

PURPOSE

Disruption in the balance of shoulder stability can produce a widely varied spectrum of clinical symptoms, ranging from minor shoulder instability to frank shoulder dislocation, followed by recurrent instability. In this study, a series of patients suffering from minor shoulder instability, all with clinical signs of preoperative subacromial impingement associated with instability, were treated. The shoulder instability alone was addressed, with the aim of eliminating the clinical symptoms of subacromial impingement and pain.

MATERIAL

In this study, 20 patients with minor shoulder instability, presenting with subacromial impingement symptoms, underwent arthroscopic treatment to address capsule-labral pathology. All patients underwent a preoperative assessment by one independent physiotherapist, using Constant and WOSI scores, as well as the Castagna test, on both the affected and non-affected sides. The Hawkins test and subacromial pain in 90° of abduction and internal rotation were also evaluated. All patients followed the same rehabilitation protocol by a second physiotherapist. All patients were followed up at 6, 12 and 24 months postoperatively by the same independent physiotherapist.

RESULTS

We observed that 20/20 patients had a positive Hawkins sign at >20° of internal rotation preoperatively, while 4/19 had a positive Hawkins sign--all with less pain--at the 24-month follow-up (P < 0.0001). Moreover, 20/20 had a positive Castagna test preoperatively, while 1/20 had a positive Castagna test at the 24-month follow-up. In terms of shoulder scores, at 24 months, the Constant score had improved from a median value of 70 (51-91) preoperatively to a median value of 91 (86-100). The median WOSI score was 48.3 (12.7-78.6) preoperatively and improved to 84.9 (39.5-98.5) at 24 months postoperatively.

CONCLUSION

Minor shoulder instability is an intra-articular pathology presenting with extra-articular subacromial impingement symptoms. By treating the intra-articular pathology, the extra-articular symptoms can be relieved in the vast majority of patients.

Alteration in shoulder kinematics and associated muscle activity in people with idiopathic scoliosis

STUDY DESIGN

A cross-sectional control-matched study in adolescents with idiopathic scoliosis (IS).

OBJECTIVE

To evaluate whether subjects with IS had shoulder dysfunction and associated impairment in shoulder kinematics and muscular activation.

SUMMARY OF BACKGROUND DATA

Evidence indicates that shoulder kinematics are related to shoulder pain and dysfunction. Despite the degree of morbidity associated with altered shoulder kinematics likely to occur in subjects with IS, no report has been published to address this hypothesis.

METHODS

In this investigation, shoulder kinematics (scapular tipping, scapular upward rotation, and scapulohumeral rhythm) and associated muscular activities [upper trapezius (UT), lower trapezius (LT), serrantus anterior (SA), and middle deltoid (MD)] were evaluated with a 3-dimensional electromagnetic tracking device and electromyography during arm elevations in 13 female subjects with IS and 13 age-gender-dominant hand-matched controls. Additionally, self-reported Flexilevel Scale of Shoulder Function (FLEX-SF) was evaluated between the 2 groups.

RESULTS

Subjects with IS demonstrated lower FLEX-SF scores than the controls (P = 0.01). For the convex side, more anterior tilt of the scapula in resting position was identified (P = 0.006). For the concave side, more scapular upward rotation in resting position was identified (P = 0.01). For the EMG amplitude, higher LT contraction activity on the convex side and lower LT and SA contraction activity on the concave side were established (P = 0.007 and less than 0.01, respectively). A moderate positive association was found between scapular posterior tipping during movement and FLEX-SF functional score (R = 0.51). A moderate negative association was found between LT muscular activity and FLEX-SF functional score (R = -0.54).

CONCLUSION

Given the progressive nature of IS and kinematic linkage among the thoracic spine, scapula, and arm, inadequate posterior tipping movement and high LT muscular activity on the convex side of IS are important to consider in rehabilitation programs for subjects with IS.

Long-term patient satisfaction and functional outcome 8-11 years after subacromial decompression

The aim of this investigation was to evaluate the long-term outcome of arthroscopic subacromial decompression (ASD) in patients with primary impingement syndrome stage II and early stage III. Ninety-five patients (105 shoulders, 48 female), mean age 54 years (range 26-69), who had undergone surgery between 1996 and 1999, were included. Pain intensity during activity and at rest, patient satisfaction, active range of motion (ROM), muscular strength and shoulder function using the Constant score were evaluated. Fifty-three (50%) shoulders were pain-free (Visual Analogue Scale < or = 10 mm) during activity and 72 (68%) shoulders were pain-free at rest. Sixty-one (58%) patients stated that they were very satisfied and 27 (25%) were quite satisfied with regard to their current shoulder function. Shoulders were divided into Group 1: Pain-free patients (n = 53), Group 2: Patients with shoulder pain and no arthropathy (n = 41) and Group 3: Patients with shoulder pain and arthropathy (n = 11). The groups had average active ROM of 157 degrees, 135 degrees and 117 degrees, respectively, in abduction and 97 degrees, 79 degrees, and 68 degrees in external rotation. The average strength in elevation in the scapular plane was 7.4, 5.8 and 3.9 kg, respectively, whereas the mean value in external rotation was 8.4, 7.9 and 5.3 kg, respectively. The Constant score had a mean value of 87, 69 and 59 points in the three groups, respectively. Eleven shoulders have undergone re-operation, one after a new trauma. We conclude that ASD is a valuable procedure. Patients expressed a high degree of satisfaction with shoulder function 8-11 years after ASD.

Clinical assessment of scapular positioning in musicians: an intertester reliability study

CONTEXT

The reliability of the measurement of the distance between the posterior border of the acromion and the wall and the reliability of the modified lateral scapular slide test have not been studied. Overall, the reliability of the clinical tools used to assess scapular positioning has not been studied in musicians.

OBJECTIVE

To examine the intertester reliability of scapular observation and 2 clinical tests for the assessment of scapular positioning in musicians.

DESIGN

Intertester reliability study.

SETTING

University research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Thirty healthy student musicians at a single university.

MAIN OUTCOME MEASURE(S)

Two assessors performed a standardized observation protocol, the measurement of the distance between the posterior border of the acromion and the wall, and the modified lateral scapular slide test. Each assessor was blinded to the other's findings.

RESULTS

The intertester reliability coefficients (kappa) for the observation in relaxed position, during unloaded movement, and during loaded movement were 0.41, 0.63, and 0.36, respectively. The kappa values for the observation of tilting and winging at rest were 0.48 and 0.42, respectively; during unloaded movement, the kappa values were 0.52 and 0.78, respectively; and with a 1-kg load, the kappa values were 0.24 and 0.50, respectively. The intraclass correlation coefficient (ICC) of the measurement of the acromial distance was 0.72 in relaxed position and 0.75 with the participant actively retracting both shoulders. The ICCs for the modified lateral scapular slide test varied between 0.63 and 0.58.

CONCLUSIONS

Our results demonstrated that the modified lateral scapular slide test was not a reliable tool to assess scapular positioning in these participants. Our data indicated that scapular observation in the relaxed position and during unloaded abduction in the frontal plane was a reliable assessment tool. The reliability of the measurement of the distance between the posterior border of the acromion and the wall in healthy musicians was moderate.