Errors in Shoulder Joint Position Sense Mainly Come from the Glenohumeral Joint

THE INTER-RATER AND INTRA-RATER RELIABILITY OF GLENOHUMERAL JOINT POSITION AND MOVEMENT SENSE TESTS APPLIED USING AN ISOKINETIC DYNAMOMETER

Purpose: The aim of this study was to test the inter-rater and intra-rater reliability of glenohumeral joint (GHJ) position and movement sense tests of an isokinetic dynamometer in healthy individuals. Methods: The study included 17 healthy subjects. GHJ position and movement sense tests were applied with an isokinetic dynamometer to the dominant extremity. Results: The different error types calculated for position sense were in the range of mean 0.02±1.62 - 5.42±1.74. The ICC value for the different error types was determined in the range of 0.038 - 0.657 for the intra-rater tests, and 0.095 - 0.779 for the inter-rater tests. The movement sense test results for different directions and angles ranged from 9.61±2.61 to 11.18±2.89. The ICC values for movemeent sense were in the range of 0.687 – 0.912 for the intra-rater tests, and 0.844 - 0.925 for the inter-rater tests. Conclusion: The isokinetic dynamometer showed moderate-good intra-rater and inter-rater test reliability in the measurement of the GHJ internal rotation movement sense. The intra-rater test reliability was poor in external rotation but the inter-rater test reliability was moderate-good. However in the measurement of movement sense, the isokinetic dynamometer showed intra-rater and inter-rater test reliability at an excellent level. The conformity of both the position and the movement sense tests, and therefore, the repeatability, was extremely good.

Variability of shoulder girdle proprioception in 44 healthy volunteers

BACKGROUND

Improved knowledge of normal shoulder girdle proprioception should benefit the treatment and rehabilitation of shoulder disorders. Whereas many of the available methods for assessing joint position sense (JPS) are costly and complex, Balke et al. have described a simple test. The primary objective of this study was to use this test to identify factors that influence shoulder-girdle JPS evaluation in healthy individuals. The secondary objective was to determine reference values based on the values obtained and on the factors associated with their variability.

HYPOTHESIS

Age and dominant limb influence the results of shoulder girdle JPS evaluation, creating a need for reference values that take these factors in account.

PATIENTS AND METHODS

A single-centre prospective study of healthy volunteers was performed between September 2012 and January 2013. In each volunteer, shoulder repositioning accuracy was assessed bilaterally as described by Balke et al. A line was drawn on the floor parallel to and 1 metre away from a wall. A target on the wall showed marks corresponding to three angles of arm elevation: 55°, 90°, and 125°. The volunteer was asked to raise the arm to the three positions, in abduction and in flexion, while memorising the joint positions, then to replicate the same positions with the eyes closed. The absolute differences between the replicated positions and the reference positions, designated angle deviations, were measured in degrees. Age, sex, and dominant upper limb were recorded.

RESULTS

The 88 shoulders of 44 healthy volunteers were studied. No significant difference was found between males and females (p>0.05). The only significant difference between sides was better replication by the dominant arm of flexion at 55° (p=0.03). By univariate analysis, age was the only factor significantly associated with repositioning errors (p=0.003); neither dominant limb nor sex were significant (p=0.29 and p=0.59, respectively). In flexion, the angle deviation increased significantly with movement amplitude. The measurements were used to create a chart of expected angle deviations in healthy individuals according to age and to plane and amplitude of movement.

DISCUSSION

The test described by Balke et al. is simple and feasible in everyday practice. Age, dominance, and plane of movement should be considered when evaluating abnormal shoulders. Further studies in larger numbers of individuals are needed to better define normal angle deviations related to these factors.

LEVEL OF EVIDENCE

IV.

Quantifying the three-dimensional joint position sense of the shoulder

Joint position sense is important for performing activities of daily living and recreational activities. The objective of this study was to develop new insights into the proprioceptive capabilities of the shoulder using a novel virtual reality paradigm where participants actively recreated shoulder positions in all three dimensions. This allows for better identification of changes in joint position sense across different shoulder postures. Ten males and ten female healthy adults matched a cursor controlled by shoulder rotations calculated from motion capture tracking, to a target shoulder position presented in a virtual environment with the use of a virtual reality headset. Four elevation angles, three plane of elevation angles, and three rotation angles were investigated, totaling thirty-six angles that encompassed the range of motion of the shoulder. Joint position sense was enhanced as the elevation angle was increased, and further enhanced when the arm was more externally rotated and elevated. As elevation angle increased to 90°, joint position sense significantly increased. There was also a significant interaction of external rotation on elevation angle. As elevation angle increased, participants were more accurate when the arm was externally, but exhibited greater variability. These improvements in joint position sense are likely produced by increased tension in muscles and capsuloligamentous mechanoreceptors within the shoulder. As many sports and activities of daily living require joint position sense to complete a task, the ability to elevate and externally rotate is important for adequate shoulder proprioception and control.

Bilateral shoulder proprioception deficit in unilateral anterior shoulder instability

HYPOTHESIS AND BACKGROUND

Proprioception is an important element of shoulder dynamic stability. It has been shown to be affected in cases of capsular or labral injuries of the glenohumeral joint. Therefore, this study was conducted to investigate bilateral shoulder proprioception by active reproduction of joint position both in patients with post-traumatic recurrent unilateral shoulder instability and in normal healthy volunteers.

METHODS

We compared 41 patients, comprising 11 female and 30 male patients with an average age of 25.6 years (range, 18-39 years), with post-traumatic unilateral anterior shoulder instability with a control group of 27 healthy volunteers with no history of shoulder problems and with normal shoulder function during examination. All patients were examined using a high-accuracy computer-controlled electronic goniometer (Propriometer). The error of active reproduction of joint position (EARJP) was measured in abduction, flexion, external rotation, and internal rotation in both shoulders.

RESULTS

We observed a significant deficit in the EARJP in the unstable shoulders within the instability group. Surprisingly, similar results were recorded for the contralateral, unaffected shoulders within this group of patients compared with the control group. Joint acuity increased with higher elevation of the arm position.

CONCLUSION

Unilateral shoulder injuries, resulting in instability, affect proprioception in both shoulders, as demonstrated by an increased EARJP. This is the first report of unilateral shoulder instability coexisting with inferior proprioception in both shoulders.

Effects of Kinesiology Taping on Scapular Reposition Accuracy, Kinematics, and Muscle Activity in Athletes With Shoulder Impingement Syndrome: A Randomized Controlled Study

CONTEXT

Scapular proprioception is a key concern in managing shoulder impingement syndrome (SIS). However, no study has examined the effect of elastic taping on scapular proprioception performance.

OBJECTIVE

To investigate the immediate effect of kinesiology taping (KT) on scapular reposition accuracy, kinematics, and muscle activation in individuals with SIS.

DESIGN

Randomized controlled study.

SETTING

Musculoskeletal laboratory, National Yang-Ming University, Taiwan.

PARTICIPANTS

Thirty overhead athletes with SIS.

INTERVENTIONS

KT or placebo taping over the upper and lower trapezius muscles.

MAIN OUTCOME MEASURES

The primary outcome measures were scapular joint position sense, measured as the reposition errors, in the direction of scapular elevation and protraction. The secondary outcomes were scapular kinematics and muscle activity of the upper trapezius, lower trapezius, and serratus anterior during arm elevation in the scapular plane (scaption).

RESULTS

Compared with placebo taping, KT significantly decreased the reposition errors of upward/downward rotation (P = .04) and anterior/posterior tilt (P = .04) during scapular protraction. KT also improved scapular kinematics (significant group by taping effect for posterior tilt, P = .03) during scaption. Kinesiology and placebo tapings had a similar effect on upper trapezius muscle activation (significant taping effect, P = .003) during scaption.

CONCLUSIONS

Our study identified the positive effects of KT on scapular joint position sense and movement control. Future studies with a longer period of follow-up and clinical measurement might help to clarify the clinical effect and mechanisms of elastic taping in individuals with SIS.

Hypermobility in Adolescent Athletes: Pain, Functional Ability, Quality of Life, and Musculoskeletal Injuries

Study Design Cross-sectional. Background Generalized joint hypermobility (GJH) may increase pain and likelihood of injuries and also decrease function and health-related quality of life (HRQoL) in elite-level adolescent athletes. Objective To assess the prevalence of GJH in elite-level adolescent athletes, and to study the association of GJH with pain, function, HRQoL, and musculoskeletal injuries. Methods A total of 132 elite-level adolescent athletes (36 adolescent boys, 96 adolescent girls; mean ± SD age, 14.0 ± 0.9 years), including ballet dancers (n = 22), TeamGym gymnasts (n = 57), and team handball players (n = 53), participated in the study. Generalized joint hypermobility was classified by Beighton score as GJH4 (4/9 or greater), GJH5 (5/9 or greater), and GJH6 (6/9 or greater). Function of the lower extremity, musculoskeletal injuries, and HRQoL were assessed with self-reported questionnaires, and part of physical performance was assessed by 4 postural-sway tests and 2 single-legged hop-for-distance tests. Results Overall prevalence rates for GJH4, GJH5, and GJH6 were 27.3%, 15.9%, and 6.8%, respectively, with a higher prevalence of GJH4 in ballet dancers (68.2%) and TeamGym gymnasts (24.6%) than in team handball players (13.2%). There was no significant difference in lower extremity function, injury prevalence and related factors (exacerbation, recurrence, and absence from training), HRQoL, or lengths of hop tests for those with and without GJH. However, the GJH group had significantly larger center-of-pressure path length across sway tests. Conclusion For ballet dancers and TeamGym gymnasts, the prevalence of GJH4 was higher than that of team handball players. For ballet dancers, the prevalence of GJH5 and GJH6 was higher than that of team handball players and the general adolescent population. The GJH group demonstrated larger sway in the balance tests, which, in the current cross-sectional study, did not have an association with injuries or HRQoL. However, the risk of having (ankle) injuries due to larger sway for the GJH group must be studied in future longitudinal studies. J Orthop Sports Phys Ther 2017;47(10):792-800. doi:10.2519/jospt.2017.7682.

THE ACUTE EFFECTS OF CONCENTRIC VERSUS ECCENTRIC MUSCLE FATIGUE ON SHOULDER ACTIVE REPOSITIONING SENSE

PURPOSE/BACKGROUND

Shoulder proprioception is essential in the activities of daily living as well as in sports. Acute muscle fatigue is believed to cause a deterioration of proprioception, increasing the risk of injury. The purpose of this study was to evaluate if fatigue of the shoulder external rotators during eccentric versus concentric activity affects shoulder joint proprioception as determined by active reproduction of position.

STUDY DESIGN

Quasi-experimental trial.

METHODS

Twenty-two healthy subjects with no recent history of shoulder pathology were randomly allocated to either a concentric or an eccentric exercise group for fatiguing the shoulder external rotators. Proprioception was assessed before and after the fatiguing protocol using an isokinetic dynamometer, by measuring active reproduction of position at 30 ° of shoulder external rotation, reported as absolute angular error. The fatiguing protocol consisted of sets of fifteen consecutive external rotator muscle contractions in either the concentric or eccentric action. The subjects were exercised until there was a 30% decline from the peak torque of the subjects' maximal voluntary contraction over three consecutive muscle contractions.

RESULTS

A one-way analysis of variance test revealed no statistical difference in absolute angular error (p > 0.05) between concentric and eccentric groups. Moreover, no statistical difference (p > 0.05) was found in absolute angular error between pre- and post-fatigue in either group.

CONCLUSIONS

Eccentric exercise does not seem to acutely affect shoulder proprioception to a larger extent than concentric exercise.

LEVEL OF EVIDENCE

2b.