Reliability of two devices for shoulder strength assessment: Wii Fit Balance Board and hand-held dynamometer.

Background: The aim of this study was to compare the reliability and agreement between two devices - Wii Fit Balance Board (WBB) versus Hand-Held Dynamometer (HHD) to measure isometric strength during the athletic shoulder (ASH) test in healthy amateur rugby players. Methods: Fifteen males (23.73 ± 2.8 years) completed two testing sessions. Maximal isometric contractions using the dominant arm (D) and non-dominant arm (ND) against a WBB and HHD were assessed at three angles of abduction (180°, 'I'; 135°, 'Y' and 90°, 'T'), in a prone lying position. Results: The results indicate a very large correlation between the HHD and the WBB. WBB provides acceptable reliability at I-Test D (CV = 9.97%, ICC = 0.88) and HHD in the I-Test D (CV = 8.90%, ICC = 0.94), I-Test ND (CV = 8.60%, ICC = 0.95) in peak strength values. The HHD is most reliable in D ASH I-Y-T (CV = 10.94%) and WBB (CV = 11.05%). In the ND ASH I-Y-T test, the HHD is the most reliable (CV = 12.5%) compared to the WBB (CV = 14.43%). Conclusions: These results suggest that WBB is a reliable device to assess strength in the ASH test with a very large correlation with the HHD. WBB and HHD are two affordable devices to assess isometric shoulder strength.

No Evidence of Short-term Changes in Muscle Activity Elicited by Dry Needling in Chronic Unilateral Shoulder Pain Patients.

OBJECTIVE: The aim of the study was to assess short-term changes in shoulder muscle activity elicited by dry needling in chronic unilateral shoulder pain (USP) patients. METHODS: A randomized, double-blind, placebo-controlled clinical trial was conducted, in which 30 volunteers with USP were recruited and randomly assigned to either real or sham dry needling conditions. Pain intensity scores, pressure pain threshold, glenohumeral internal rotation angles, and electromyographic activity during isotonic shoulder tasks (shoulder flexion and extension) were assessed before, immediately, and 72 hours after the intervention in the infraspinatus and deltoid muscles. RESULTS: A single application of real dry needling resulted in lower pain intensity scores and a larger range in glenohumeral internal rotation 72 hours after the intervention in comparison with sham dry needling. No differences in pressure pain threshold or muscle activity were observed due to the intervention. DISCUSSION: A single application of real dry needling resulted in clinically significant changes in the short term. No differences were detected in muscle activation in the infraspinatus or deltoid muscles. Complementary interventions and longer follow-up times may be required to observe changes in muscle activity.

Muscle responses during radial nerve-biased upper limb neurodynamic test in asymptomatic individuals: a cross-sectional study.

This laboratory cross-sectional study aimed at explore the muscle response (MR) of the upper trapezius, infraspinatus, biceps brachii and extensor carpi radialis brevis (ECRB) during the radial nerve-biased upper limb neurodynamic test (RN-ULNT) in healthy participants. Myoelectric activity was stage-by-stage recorded during two sequencing variants of the RN-ULNT: S1, in which elbow extension was the last movement; and S2, in which wrist flexion was the last movement. Final elbow and wrist joint angle and sensory response (SR) in five zones (Z1-Z5) were also registered. MR was qualitatively categorized as 'absent' (No-MR), 'true' (TMR) or 'uneven' (UMR). In both sequences, significant increases in muscle activity occurred mostly during shoulder abduction and elbow extension (p ≤ 0.009). Also, elbow extension but not wrist flexion increased the activity of the ECRB muscle (p ≤ 0.009). S2 showed significantly higher upper trapezius (p = 0.04) and biceps brachii (p = 0.036) muscle activity during wrist flexion, and higher report of SR in Z1 and Z4 (p < 0.001) compared to S1. Only the ECRB muscle showed significant differences in the MR type between S1 and S2 (TMR, p = 0.016; UMR, = 0,012). Our results may be useful in the assessment of upper limb musculoskeletal disorders.

Pressure pain threshold mappings of the infraspinatus muscle in chronic unilateral shoulder pain patients do not reflect generalized hypersensitivity.

OBJECTIVES: Increased mechanical sensitivity has been observed on the unaffected side in chronic pain conditions, suggesting generalized or widespread hypersensitivity. However, this cannot be considered as a universal response since this hypersensitivity is inconsistent across muscle pain pathologies. The aim of this study was to assess generalized hypersensitivity in chronic unilateral shoulder pain, using pressure pain threshold (PPT) mappings of the infraspinatus muscle. The proposed evaluation is based on the assessment of PPT on a limited subset of sites, reducing potential habituation or sensitization effects. METHODS: Twenty-nine patients with unilateral shoulder pain (USP) and twenty-seven healthy volunteers were recruited. PPT was assessed using a manual pressure algometer. Six sites distributed over the infraspinatus muscle were assessed, and three repetitions were performed at each site. Mappings were derived using two-dimensional interpolation. RESULTS: Lower PPT values were found in the symptomatic side in comparison with the asymptomatic side at all assessment sites (estimated difference: 1.42 ±â€¯0.10 kgf/cm2, p < 0.001), but there were no differences among the asymptomatic side of USP patients and any of the sides in healthy volunteers (largest estimated difference: 0.17 ±â€¯0.28 kgf/cm2, p = 0.927). Furthermore, the medial region of the infraspinatus muscle showed higher mechanical sensitivity in both healthy volunteers and USP patients. CONCLUSIONS: These results suggest that USP does not induce generalized hypersensitivity, in contrast with previously reported findings. Physiotherapists could take these results into account for the assessment and treatment of patients with USP.