Henrik Eshøj

Translation, adaptation and measurement properties of an electronic version of the Danish Western Ontario Shoulder Instability Index (WOSI)

Objectives To translate and adapt the Western Ontario Shoulder Instability (WOSI) questionnaire into Danish and, to evaluate measurement properties of an electronic Danish WOSI version. Methods The Swedish WOSI version was used for translation and adaptation into Danish followed by examination of test-retest reproducibility (14-day interval) besides concurrent and construct validity. Concurrent validity was examined by comparing WOSI in paper version with an electronic version, whereas construct validity was examined by comparing WOSI with Numeric Pain Rating Scale (NPRS) and the Oxford Shoulder Score (OSS). Reproducibility was evaluated with Intraclass correlations (ICC), Standard Error of Measurement (SEM), minimal detectable change (MDC) and limits of agreement (LOA). Validity was evaluated with Pearson’s (r) and Concordance Correlation Coefficients (CCC). Results 41 subjects (median age 34, range 18–57) were included in the analysis of reproducibility. An ICC of 0.97 (95% CI 0.95 to 0.99) for the total WOSI score was found. SEM was 100.1, resulting in an MDC of 277.5 and LOAs within the range of -246.4 and 308.6. 25 subjects (median age 34, range 18–72) were included in the analysis of concurrent validity obtaining a CCC of 0.96 (95% CI 0.91 to 0.98). Construct validity was investigated in 62 subjects (median age 31, range 18–72) obtaining correlations of 0.83 (95% CI 0.68 to 0.97) (NPRS) and 0.79 (95% CI 0.62 to 0.94) (OSS). Conclusions An electronic Danish version of WOSI presented excellent test-retest reproducibility and acceptable measurement errors. Also, concurrent validity between paper and electronic version was highly satisfactory as was the construct validity. Surprisingly, though, the NPRS correlated more with WOSI than OSS.

Intertester reliability of clinical shoulder instability and laxity tests in subjects with and without self-reported shoulder problems

Objective First, to investigate the intertester reliability of clinical shoulder instability and laxity tests, and second, to describe the mutual dependency of each test evaluated by each tester for identifying self-reported shoulder instability and laxity. Methods A standardised protocol for conducting reliability studies was used to test the intertester reliability of the six clinical shoulder instability and laxity tests: apprehension, relocation, surprise, load-and-shift, sulcus sign and Gagey. Cohen’s kappa (κ) with 95% CIs besides prevalence-adjusted and bias-adjusted kappa (PABAK), accounting for insufficient prevalence and bias, were computed to establish the intertester reliability and mutual dependency. Results Forty individuals (13 with self-reported shoulder instability and laxity-related shoulder problems and 27 normal shoulder individuals) aged 18–60 were included. Fair (relocation), moderate (load-and-shift, sulcus sign) and substantial (apprehension, surprise, Gagey) intertester reliability were observed across tests (κ 0.39–0.73; 95% CI 0.00 to 1.00). PABAK improved reliability across tests, resulting in substantial to almost perfect intertester reliability for the apprehension, surprise, load-and-shift and Gagey tests (κ 0.65–0.90). Mutual dependencies between each test and self-reported shoulder problem showed apprehension, relocation and surprise to be the most often used tests to characterise self-reported shoulder instability and laxity conditions. Conclusions Four tests (apprehension, surprise, load-and-shift and Gagey) out of six were considered intertester reliable for clinical use, while relocation and sulcus sign tests need further standardisation before acceptable evidence. Furthermore, the validity of the tests for shoulder instability and laxity needs to be studied.

Sensorimotor control and neuromuscular activity of the shoulder in adolescent competitive swimmers with generalized joint hypermobility

INTRODUCTION Shoulder pain is highly prevalent in competitive swimmers, and generalized joint hypermobility (GJH) is considered a risk factor. Sensorimotor control deficiencies and altered neuromuscular activation of the shoulder may represent underlying factors. RESEARCH QUESTION To investigate whether competitive swimmers with GJH including shoulder hypermobility (GJHS) differ in shoulder sensorimotor control and muscle activity from those without GJH and no shoulder hypermobility (NGJH). METHODS Competitive swimmers (aged 13-17) were recruited. GJHS or NGJH status was determined using the Beighton score (0-9) and Rotès-Quérol test (positive/negative). Inclusion criteria for GJHS were a Beighton score ≥5 and minimum one hypermobile shoulder, while NGJH was defined as a Beighton score ≤3 and no shoulder hypermobility. Three prone lying, upper-extremity weight-bearing shoulder stabilometric tests were performed on a force platform: Bilateral upper-extremity support eyes open (BL-EO) and eyes closed (BL-EC) and unilateral upper-extremity support eyes open (UL-EO). Surface electromyography (SEMG) was measured from the upper trapezius, lower trapezius, serratus anterior, infraspinatus and pectoralis major muscles. SEMG was normalized using maximal voluntary isometric contractions and presented relative to maximal voluntary SEMG (%MVE). Co-contraction index (CCI) was calculated for the following muscle pairs: upper trapezius-lower trapezius, upper trapezius-serratus anterior, and infraspinatus-pectoralis major. Between-group differences in stabilometric parameters, %MVE, and CCI were analyzed with a mixed effects model. RESULTS Thirty-eight swimmers were enrolled as GJHS (n = 19) or NGJH (n = 19). There were no group differences in stabilometric parameters or CCI. GJHS displayed significantly decreased (29%) pectoralis major activity during BL-EO compared to NGJH (5.35 ± 1.77%MVE vs. 7.51 ± 1.96%MVE; p = 0.043). SIGNIFICANCE Adolescent competitive swimmers with GJHS displayed no shoulder sensorimotor control deficiencies and no generally altered shoulder muscle activity pattern, except for decreased pectoralis major activity in BL-EO. Longitudinal studies are needed to investigate whether decreased pectoralis major activation contributes to the development of shoulder pain in swimmers with GJHS.