Scapular positioning and motor control in children and adults: A laboratory study using clinical measures

Inter-rater and intra-rater reliability of a movement control test in shoulder

BACKGROUND

Movement faults are commonly observed in patients with musculoskeletal pain. The Kinetic Medial Rotation Test (KMRT) is a movement control test used to identify movement faults of the scapula and gleno-humeral joints during arm movement. Objective tests such as the KMRT need to be reliable and valid for the results to be applied across different clinical settings and patient populations. The primary objective of the present study was to determine the intra-rater and inter-rater reliability of KMRT in subjects with and without shoulder pain.

METHODS

Sixty subjects were included in this study based on specific inclusion and exclusion criteria. Two musculoskeletal physiotherapists with different levels of clinical experience performed the tests. The intra-rater reliability was tested in twenty asymptomatic subjects by a single assessor at two week intervals. An equal number of subjects with and without shoulder pain were tested by both the assessors to determine the inter-rater reliability. Both components of the KMRT, the Gleno- Humeral Anterior Translation (GHAT) and the Scapular Forward Tilt (SCFT) were tested.

RESULTS

The Kappa values for inter-rater reliability of the GHAT and SCFT were K = 0.68 & K = 0.65 respectively in subjects with shoulder pain. In asymptomatic subjects, the inter-rater reliability of GHAT was K = 0.61 and SCFT was K = 0.85. Intra-rater reliability ranged from K = 0.66 for GHAT to K = 0.87 for SCFT.

CONCLUSION

Our study found substantial agreement in inter-rater reliability of KMRT in subjects with shoulder pain, whereas substantial to near perfect agreement was found in intra-rater and inter-rater reliability of KMRT in subjects without shoulder pain.

Inter-rater reliability of shoulder measurements in middle-aged women

OBJECTIVES

To investigate inter-rater reliability of a set of shoulder measurements including inclinometry [shoulder range of motion (ROM)], acromion-table distance and pectoralis minor muscle length (static scapular positioning), upward rotation with two inclinometers (scapular kinematics) and pain pressure thresholds (muscle tenderness) in middle-aged women.

DESIGN

Observational study.

PARTICIPANTS

Thirty symptom-free middle-aged women (first cohort) were measured by two raters. All measurements with an intraclass correlation coefficient (ICC) below 0.75 were retested after an additional training period in a second cohort of 30 symptom-free middle-aged women.

MAIN OUTCOME MEASURES

Inter-rater reliability of all variables was measured with the ICC (95% confidence interval) and standard error of measurement (SEM).

RESULTS

Acromion-table distance (ICC=0.91, SEM 0.22 to 0.28% of body length), pectoralis minor muscle length (ICC=0.91, SEM 0.16% of body length), pain pressure thresholds (ICC=0.78 to 0.85, SEM 0.39 to 0.70kg) and abduction ROM (ICC=0.77, SEM 5°) showed good to excellent inter-rater reliability in the first cohort. After an additional training period, forward flexion ROM showed good inter-rater reliability (ICC=0.83, SEM 5°), scapular upward rotation in resting position showed moderate reliability (ICC=0.52, SEM 2°), and other scaption angles showed weak reliability (ICC=0.26 to 0.43, SEM 3 to 8°).

CONCLUSIONS

In a battery of clinical tools to evaluate factors contributing to shoulder pain, static scapular positioning and pressure pain thresholds were found to have good to excellent inter-rater reliability in middle-aged women. Additional training is recommended for measurements with a gravity inclinometer.

Scapulohumeral control after stroke: A preliminary study of the test-retest reliability and discriminative validity of a clinical scapular protocol (ClinScaP)

BACKGROUND

Clinical scapulohumeral tests are lacking post-stroke.

OBJECTIVE

To test reliability and discriminant validity of clinical scapulohumeral assessments post-stroke.

METHODS

Following tests were assessed in 57 individuals with stroke (IwS) (subdivided in a low, moderate, high proximal arm function (PAF) group) and 15 healthy controls: (1) Observation of tilting/winging; (2) shoulder girdle position tests (pectoralis minor index, acromial index, scapular distance test); (3) scapular lateral rotation measurement; (4) maximal humeral elevation and (5) medial rotation test were executed. 15 IwS were measured twice by the same assessor to determine test-retest reliability. Differences between controls and IwS and between IwS with different levels of PAF were assessed.

RESULTS

ICCs were very high for all tests (>0.80), except the pectoralis minor index (0.66). Weighted Kappas were high for observation and the medial rotation test (>0.70). Group differences were found for observation, lateral rotation and humeral elevation. IwS compared to controls, and IwS with lower compared to higher PAF generally showed increased lateral rotation (p < .01); decreased maximal active humeral elevation (p < .001); and more often tilting and winging (p < .05).

CONCLUSIONS

The use of these tests in clinical settings will allow for identification of altered scapular characteristics, which will enhance treatment planning for PAF post-stroke.

Reliability and Validity of the Measurement of Scapular Position Using the Protractor Method

BACKGROUND

The protractor method is a proposed clinical assessment tool, the first to measure vertical scapular position, that directly compares scapular and spinal landmarks. This tool has the potential to reliably and accurately measure excessive scapular elevation or depression.

OBJECTIVE

The purpose of this study was to determine reliability and validity of the protractor method to measure resting scapular position.

DESIGN

An interrater and intratester reliability and validity study was conducted.

METHODS

Testing was conducted on the same day by 2 physical therapists who were blinded to each other's results. The vertical distances between the spinous process of C7 and the superior margin of the medial aspect of the spine of the scapula (C7 method) and the spinous process of T8 and the inferior angle of the scapula (T8 method) were palpated and measured on the symptomatic shoulder in 34 people with current shoulder pain using the protractor method. Measurements were compared with 2-dimensional camera analysis to assess validity.

RESULTS

For intertester reliability, the standard error of measure, minimal detectable change, and intraclass correlation coefficient were 6.3 mm, 17.3 mm, and .78, respectively, for the C7 method and 5.7 mm, 15.7 mm, and .82, respectively, for the T8 method. For intratester reliability, the standard error of measure, minimal detectable change, and intraclass correlation coefficient were <0.9 mm, <2.5 mm, and .99, respectively. For validity, significant correlations (r) and mean differences were .83 and 10.1 mm, respectively, for the C7 method and .92 and 2.2 mm, respectively, for the T8 method.

LIMITATION

The results of this study are limited to static measurement of the scapula in one plane.

CONCLUSION

Both protractor methods were shown to have good reliability and acceptable validity, with the T8 method demonstrating superior clinical utility. The clinical use of the T8 method is recommended for measurement of excessive resting scapular elevation or depression.

The pectoralis minor muscle and shoulder movement-related impairments and pain: Rationale, assessment and management

The adaptive shortening or tightness of the pectoralis minor muscle (PMm) is one of the potential biomechanical mechanisms associated with altered scapular alignment at rest and scapular motion during arm elevation (scapular dyskinesis) in patients with shoulder complaints. This masterclass briefly reviews the role of the PMm in shoulder movement-related impairments and provides a critical overview of the assessment of PMm tightness and the conventional approaches to increase its resting length and extensibility. A rehabilitation approach focused on PMm stretching and simultaneous optimization of the kinematic chain of arm elevation is also discussed, hoping to improve the management of shoulder movement-related impairments and pain.

The comparison of scapular upward rotation and scapulohumeral rhythm between dominant and non-dominant shoulder in male overhead athletes and non-athletes

Previous studies have stated that the scapulohumeral rhythm dysfunction can make person prone to glenohumeral joint pathologies. The purpose of this study was to compare scapular upward rotation and scapulohumeral rhythm between dominant and non-dominant shoulder in male overhead athletes and non-athletes. Seventeen overhead athletes and seventeen non-athletes volunteered for this study. Two inclinometers were used to measure humeral abduction and scapular upward rotation in rest position, 45°, 90° and 135° humeral abduction in frontal plane. Findings indicated there was no significant asymmetry in scapular upward rotation and scapulohumeral rhythm in different abduction angles between dominant and non-dominant shoulder in non-athletes. In contrast, overhead athletes' dominant shoulders have more downward rotation in scapular rest position and more upward rotation in 90° and 135° shoulder abduction than non-dominant shoulders. Also, overhead athletes presented scapulohumeral rhythm asymmetry between dominant and non-dominant shoulder in 90° and 135° humeral abduction as dominant shoulders have less scapulohumeral rhythm ratio than non-dominant shoulders. Furthermore, overhead athletes dominant shoulders have more scapular downward rotation in scapular rest position, more scapular upward rotation in 90° and 135° humeral abduction and less scapulohumeral rhythm ratio in 45°, 90° and 135° humeral abduction than non-athletes in dominant shoulders. We suggest that clinicians should be aware that some scapular asymmetry may be common in some athletes. It should not be considered as a pathological sign but rather an adaptation to extensive use of upper limb.

Clinical assessment of scapula and hip joint function in preadolescent and adolescent baseball players

BACKGROUND

Proper scapulothoracic and hip mechanics are essential aspects of the throwing kinetic chain. Little is known regarding these entities in preadolescent and adolescent baseball players.

HYPOTHESIS

Scapular malposition and dyskinesis as well as hip dysfunction are highly prevalent in preadolescent and adolescent baseball players and may be identified by simple clinical testing.

STUDY DESIGN

Descriptive laboratory study.

METHODS

A total of 112 baseball players aged 7 to 18 years were recruited from local Little Leagues, traveling teams, and high schools. Participants were divided into 2 groups: preadolescents (players aged 7-12 years) and adolescents (players aged 13-18 years). Scapular symmetry was tested with the yes/no method of Kibler and by measuring forward shoulder posture via the "coracoid distance." Hip abductor strength was measured by use of a handheld digital dynamometer. Functional gluteal and core strength was assessed by video analysis of the subjects performing the single-legged squat test. Hip range of motion was measured in the prone position by use of a handheld goniometer.

RESULTS

Compared with the preadolescent group, the adolescent group had a significantly higher prevalence of scapular dyskinesis in the throwing shoulder (50% vs 25.9%, P = .011). The adolescents had significantly higher normalized hip abduction strength in both the stride (17.41 vs 12.62 N/kg, P < .001) and stance (17.82 vs 12.61 N/kg, P < .001) legs. The preadolescent group was unable to perform the single-legged squat test correctly in either the stance (0% preadolescent vs 13% adolescent, P = .0127) or stride (0% preadolescent vs 9.3% adolescent, P = .0567) leg. The mean coracoid distance was elevated in the dominant (throwing) shoulder after controlling for scapular dyskinesis (P < .0001). Presence of scapular dyskinesis was associated with a higher mean coracoid distance (P = .0067).

CONCLUSION

There was a high prevalence of dominant shoulder scapular dyskinesis in the adolescent compared with the preadolescent group, as well as universally poor single-legged squat test performance. The mean coracoid distance was higher in the dominant or throwing side compared with the nondominant side independent of scapular dyskinesis. Presence of scapular dyskinesis was associated with higher mean coracoid distance.

CLINICAL RELEVANCE

Identification of players thought to be at increased risk for throwing injuries and initiation of targeted rehabilitation programs may decrease injury rates in preadolescent and adolescent baseball players.

The suitability of sham treatments for use as placebo controls in trials of spinal manipulative therapy: a pilot study

Despite the augmented use and dependence on manual therapy (MT), there are still calls from both within and outside the MT professions to provide robust evidence that spinal manipulative therapy (SMT) induces therapeutic effects beyond placebo. To facilitate this, placebo or 'sham' treatments, the development of which is notoriously difficult, must be used in rigorously controlled trials. The aim of this study was to investigate the suitability of different shams as controls in SMT trials. A repeated measures, single-blind, randomised trial was conducted on 10 asymptomatic subjects. Pain pressure thresholds (PPTs) were measured at 2 sites, local and systemic, before and after the application of either high-velocity low-amplitude thrust (HVLAT), sham functional technique (SFT), sham ultrasound (SUS) or no intervention control (NIC) to the cervico-thoracic (CT) junctional area. Treatment credibility was then assessed using a 4-point Likert Scale in response to 4 statements. Results demonstrated no significant change in PPT following any of the interventions, irrespective of site tested. The effect sizes for all interventions were considered small (d = <0.2). There were significant differences in Likert Scale responses for each statement (P < 0.001), with SUS eliciting significantly different responses as compared to SFT and NIC but not, predominantly, with HVLAT. SUS is implicated as being the most effective sham, having high fidelity to subjects' perceptions of a 'real' treatment, whilst being therapeutically inert i.e. results in no significant change in clinical status.

Scapula alata in early breast cancer patients enrolled in a randomized clinical trial of post-surgery short-course image-guided radiotherapy

BACKGROUND

Scapula alata (SA) is a known complication of breast surgery associated with palsy of the serratus anterior, but it is seldom mentioned. We evaluated the risk factors associated with SA and the relationship of SA with ipsilateral shoulder/arm morbidity in a series of patients enrolled in a trial of post-surgery radiotherapy (RT).

METHODS

The trial randomized women with completely resected stage I-II breast cancer to short-course image-guided RT, versus conventional RT. SA, arm volume and shoulder-arm mobility were measured prior to RT and at one to three months post-RT. Shoulder/arm morbidities were computed as a post-RT percentage change relative to pre-RT measurements.

RESULTS

Of 119 evaluable patients, 13 (= 10.9%) had pre-RT SA. Age younger than 50 years old, a body mass index less than 25 kg/m2, and axillary lymph node dissection were significant risk factors, with odds ratios of 4.8 (P = 0.009), 6.1 (P = 0.016), and 6.1 (P = 0.005), respectively. Randomization group was not significant. At one to three months' post-RT, mean arm volume increased by 4.1% (P = 0.036) and abduction decreased by 8.6% (P = 0.046) among SA patients, but not among non-SA patients. SA resolved in eight, persisted in five, and appeared in one patient.

CONCLUSION

The relationship of SA with lower body mass index suggests that SA might have been underestimated in overweight patients. Despite apparent resolution of SA in most patients, pre-RT SA portended an increased risk of shoulder/arm morbidity. We argue that SA warrants further investigation. Incidentally, the observation of SA occurring after RT in one patient represents the second case of post-RT SA reported in the literature.