Joseph M. Day

Thickness of the lower trapezius and serratus anterior using ultrasound imaging during a repeated arm lifting task.

The purposes of this study were to establish the reliability for measuring scapular muscle thickness, and to examine how scapular muscle thickness changes with respect to external loads. Participants were asymptomatic subjects recruited from a sample of convenience. Thickness Measures were taken using rehabilitative ultrasound imaging (RUSI) under 11 conditions, rest and 10 progressive loads, for the Lower Trapezius (LT) and Serratus Anterior (SA). The procedures were repeated 1 week later to determine reliability. Bland and Altman limits of agreement and Interclass correlation coefficients (ICC) were used to determine reliability. Separate repeated measure ANOVAs were performed to determine differences in muscle thickness for both muscles across 3 conditions; rest and the 2 loaded conditions that represented the lowest and highest torque values. Results demonstrate good within and between day reliability for the LT (ICC = .86 to .99) and SA (ICC = .88 to .99). For the LT and SA, there were significant differences between the resting thickness and 2 lifting conditions (p ≤ .01) but not between the two lifting conditions. It was concluded that RUSI is reliable in measuring scapular muscle thickness. RUSI is sensitive enough to detect absolute changes in thickness from resting to a contracted state but unable to detect differences between loads imposed on the shoulder.

Scapular Muscle Performance in Individuals With Lateral Epicondylalgia

STUDY DESIGN Descriptive, laboratory-based, cross-sectional study. OBJECTIVES To describe scapular musculature strength, endurance, and change in thickness in individuals with unilateral lateral epicondylalgia (LE) compared to the uninvolved limb and the corresponding limb of a matched comparison group. BACKGROUND Reported poor long-term outcomes for the nonsurgical management of individuals with LE suggest a less-than-optimal rehabilitation process. Knowledge of scapular muscle function in a working population of individuals with LE may help to further refine conservative management of this condition. METHODS Twenty-eight patients with symptomatic LE and 28 controls matched by age and sex were recruited to participate in the study. Strength of the middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) was measured with a handheld dynamometer. A scapular isometric muscle endurance task was performed in prone. Changes in muscle thickness of the SA and LT were measured with ultrasound imaging. Analysis-of-variance models were used to determine within- and between-group differences. RESULTS The involved side of the group with LE had significantly lower values for MT strength (P = .031), SA strength (P<.001), LT strength (P = .006), endurance (P = .003), and change in SA thickness (P = .028) when compared to the corresponding limb of the control group. The involved side of the group with LE had significantly lower strength of the LT (P = .023) and SA (P = .016) when compared to the uninvolved limb; however, these differences were small and of potentially limited clinical significance. CONCLUSION When compared to a matched comparison group, there were impairments of scapular musculature strength and endurance in patients with LE, suggesting that the scapular musculature should be assessed and potentially treated in this population. Cause and effect cannot be established, as the weakness of the scapular musculature could be a result of LE.

Arm dominance does not influence measures of scapular muscle strength and endurance in healthy individuals

BACKGROUND PURPOSE: Scapular muscle performance is potentially influenced by arm dominance. The purpose of this study was to investigate the effect of arm dominance on clinical measures of scapulohumeral muscle strength and endurance. METHODS: Thirty-two healthy individuals between the ages of 30 and 65 years were recruited to participate. Scapular muscle strength of the upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) were recorded with a hand held dynamometer. One scapulohumeral isometric muscle endurance task was performed in prone. The order of testing (strength and endurance) was randomized for each individual. Dominant to non-dominant strength and endurance measures were compared with paired t-tests. RESULTS: Arm dominance was significantly higher for UT strength (p < 0.001) and endurance (p = 0.015). However, the differences between the dominant and non-dominant limbs were not beyond minimal detectable change values. CONCLUSION: It does not appear that scapulohumeral muscle strength and endurance is clinically different for the dominant and non-dominant limbs in a middle age healthy population.

Effect of Exercise Position on Percent Changes in Serratus Anterior Muscle Thickness

assessment tools have limitations. Techniques used to manual muscle test the SA are easy to perform but do not appear to isolate the SA [5]. ElectroMyographic Activity (EMG) and motion analysis provide researchers with isolated and detailed information but interpretation is difficult [7, 8]. Unlike other assessment tools, Ultrasound Imaging (UI) provides isolated real time visualization of muscle contraction, thus allowing researchers and clinicians quick interpretation of the contraction of a specific muscle [9, 10]. UI has been shown to be a valid and reliable assessment tool for measuring thickness and cross sectional areas of the transversus abdominus, obliques [11], lumbar multifidi [12], quadriceps [13], lower trapezius [14], and cervical musculature [15]; yet there is a limited body of evidence related to the psychometric properties of measuring SA thickness with UI.

Home Exercises Versus On-Site Rehabilitation in the Management of Lateral Elbow Tendinopathy: A Critically Appraised Topic

Clinical Scenario: Lateral elbow tendinopathy (LE) is a common musculoskeletal condition that often results in pain and disability. An array of conservative interventions have been shown to improve patient outcomes in outpatient rehabilitation clinics. However, with the rise in health care costs, patients and rehabilitation specialists have opted to reduce the number of in-house visits and focus on home exercise programs (HEPs). As a result, many rehabilitation specialists and patients now depend on HEPs as the primary intervention to treat LE. Focused Clinical Question: For individuals with LE, is there evidence to suggest that HEPs are as effective as traditional on-site rehabilitation for reducing pain and disability? Summary of Search, Best Evidence Appraised, and Key Findings: The literature was searched for studies comparing HEP to on-site rehabilitation in the management of LE. Two clinical controlled trials (CCTs) were included. No studies suggested that HEPs demonstrated equal or improved outcomes in pain or disability. Both studies concluded that on-site rehabilitation services were more effective at reducing pain and disability in the short term. More research is needed to compare the cost effectiveness of both HEP and on-site rehabilitation. Clinical Bottom Line: Based on 2 CCTs, it can be concluded that there is moderate evidence to suggest that patients with LE experience decreased pain and disability scores with on-site rehabilitation compared to a guided HEP in the short term. The authors could not draw a conclusion regarding long-term effects of treatments or cost effectiveness of the 2 approaches. Strength of Recommendation: Based on the Centre for Evidence Based Medicine, there is level B evidence that a HEP only was not as effective as on-site rehabilitation services in patients with LE.