Objective Generalized joint hypermobility predisposes some individuals to a wide variety of musculoskeletal complaints, especially in the shoulder joint. Proprioception, which includes joint position sense and sense of movement, has an important role in the functional stability of shoulder joint. Given the critical role of proprioception in the functional stability of shoulder, the primary aim of this study was to compare shoulder joint position sense and sense of movement (kinesthesia) between individuals with and without general joint hyper mobility. The secondary aim of this study was to compare proprioception between dominant and non-dominant sides in each group. Materials & Methods In this causal-comparative study, 20 females with generalized joint laxity (Mean[SD] age=22.05[2.30] y) and 20 females without generalized joint laxity (Mean[SD] age=22.65[2.53] y) participated in the study. Testing was performed in the supine position. Prior to beginning each proprioception tests, the participants were given to practice trials to become familiar with the testing procedure. Proprioception tests were performed during passive repositioning and kinesthesia using an isokinetic dynamometer. The shoulder external rotation range was measured with a standard goniometer, and 90% of its range was considered as a target angle in passive reposition test. The kinesthetic sense of the shoulder was evaluated by measuring the threshold for passive external rotation. The speed of threshold to detection of passive motion test was at 0.5 deg/s and passive reproduction of joint position was at 2 deg/s. Both dominant and non-dominant sides of all the subjects were evaluated. Test sequences for measuring the threshold to detection of passive motion and passive reproduction of joint position, as well as dominant and non-dominant shoulder were random. The blindfold and headphones were used to remove visual and auditory feedback. The mean of three repetitions of passive reproduction of target angle and threshold to detection of passive motion were calculated. Independent t-test was used to compare joint position sense and kinesthesia between females with and without generalized joint laxity, and paired t test was used to statistically analyze differences between dominant and non-dominant sides in each group. Results No significant difference was observed in joint position test acuity and of detection of motion in each of dominant and non-dominant sides between females with and without generalized joint laxity (dominant side: P=0.47, non-dominant: P=0.70). Females with generalized joint laxity exhibited significantly larger errors in passive joint reproduction tests in both dominant and non-dominant sides (P=0.001) compared with those without generalized joint laxity. Conclusion The results revealed that the angle repositioning sense in the extreme range of shoulder joints in females with generalized joint laxity is reduced compared to those without generalized joint laxity. Lower joint position test acuity in females with generalized join...

Purpose: Altered kinematics of the scapula or scapular dyskinesis (downward rotation, anterior tilt, and protraction) contribute to impingement syndrome by decreasing the subacromial space. Given the critical role of scapular position and movement in the function of the shoulder, the aim of this study was to compare scapular position and dyskinesis in individuals with and without rounded shoulder posture. Methods:By employing the convenience sampling method, 21 individuals with rounded shoulder posture (11 females and 10 males; average age: 22.95 years) and 23 individuals without rounded shoulder posture (13 females and 10 males; average age: 22.43 years) were enrolled in this study through a case-control design.The scapular dyskinesis test was used to observe alterations in scapulohumeral rhythm in the sagittal and frontal planes of the arm. Also, the scapular position was examined according to the Kibler test. Data were analyzed using SPSS 21. We used the Independent t-test and Mann-Whitney test to compare the differences between the two groups.Results: There were no differences in scapular dyskinesis between the two groups (P>0.05). The prevalence of subtle or obvious scapular dyskinesis in individuals with rounded shoulder posture was greater than those without rounded shoulder posture, but the difference was not statistically significant. Furthermore, no significant difference was found in static scapular position (Kibler test) of the dominant and non-dominant sides between the two groups (P>0.05). Conclusion:There were no significant differences in scapular position and scapular movement pattern between the individuals with and without rounded shoulder posture.

Rounded shoulder posture is associated with alteration in scapular and glenohumeral orientation and kinematics and muscle imbalance. →What this article adds:The result of this study showed that in individuals with rounded shoulder posture, alteration in scapular and glenohumeral orientation and kinematics may not lead to reduction of acromiohumeral distance.