Author(s): SCHUHBECK, M., TAUBE, W., KEINER, M., BEINERT, K., Institution: DEUTSCHE HOCHSCHULE FÜR GESUNDHEIT UND SPORT, Country: GERMANY, Abstract-ID: 2155

INTRODUCTION:
Chronic shoulder pain is prevalent among overhead athletes (OA), from baseball pitchers to handball players, with pitchers reaching angular velocities over 7000°/sec for internal rotations (Fleisig et al 1999). Common physical performance tests, such as the closed kinetic chain upper extremity stability test (CKCUEST) cannot differentiate athletes with and without pain (Torabi 2024), probably because they do not test the rotational aspects of overhead motion. In addition, CKCUEST provides only one sinlge outcome measure, the "number of touches". This study introduces the High Rotation Test (HRT), performed in 90° abduction, addressing speed and rotation. The aim of the study was to compare the performance of patients with shoulder pain (Experimental Group, EG) and healthy controls (Control Group, CG) on HRT and the CKCUEST. Further, we also assessed joint position sense (JPS) and pain.
METHODS:
In the study, 54 participants took part (EG, n=35, 38.3 ± 13.8 yrs.; 19 males; CG, n=19, 27.7 ± 7.2 yrs.; 9 males). Kinematic variables such as velocity (v), acceleration (a) and range of motion (ROM) were recorded for both HRT and CKCUEST, utilizing inertial motion units (IMU) (Captiv Motion System, TEA, France). IMU’s were also used to assess joint position sense (JPS). Differences between groups were analysed with student´s t-test. Effect sizes were reported with Cohen´s d and correlations between the kinematic variables and pain were calculated with Pearson correlation coefficient.
RESULTS:
Average pain intensity was 6.1 on a NRS for the EG and 0 for the CG. Significant differences in HRT performance were found between the EG and CG for repetitions [t(52) = 2.63, p = 0.011, d = 0.75] and velocity [t(52) = 2.68, p = 0.006, d = 0.82]. Further, the number of repetitions was significantly correlated to acceleration (r = .41, p = 0.002) and velocity (r = .43, p = 0.001). Regarding the CKCUEST, significant differences between EG and CG were found for repetitions [t(51) = 2.53, p = 0.015, d = 0.72] but not for velocity. Further, the number of repetitions was significantly correlated to acceleration (r = .64, p < 0.001) and velocity (r = .43, p < 0.001). Significant differences were also found for shoulder JPS [t(52) = -4.75, p < 0.001, d = 1.35]. Pain correlated with JPS (r = .39, p = 0.003) but not with velocity or acceleration.
CONCLUSION:
Both tests show differences in repetitions between EG and CG. This is of clinical importance because repetitions are easily assessed in daily routine. Differences in peak velocity were identified with the HRT, but not in the CKCUEST. This might be an important parameter for determining the return to sports, as most OA rely on very fast rotational movements. Complementary to the functional tests, the limitation of shoulder patients in the JPS test may indicate the impaired sensory component of pain. Thus, it is recommended to use the HRT in combination with the JPS test in order to test for motor and sensory impairments in OA with shoulder problems.