Objective measurement of Inferior-Directed stiffness in glenohumeral joint using a specially designed robotic device in healthy shoulders; Within- and Between-Session reliability.

Clinical assessment of capsuloligamentous structures of the glenohumeral joint has been qualitative and subjective in nature, as demonstrated by limited intra- and inter-rater reliability. Robotic devices were utilized to develop a clinically objective measurement technique for glenohumeral joint stiffness. The purpose of this study was to quantify the amount of inferior-direction stiffness of the glenohumeral joint using a safe clinical device in the asymptomatic individuals, and to determine between trial and between session reliability of the robotic device. Twenty healthy subjects were recruited via convenience sampling. Inferior-directed translation and applying force were measured using displacement and force sensors of a robotic device. The stiffness values were calculated as the mean of the slopes of the linear portions of the force-displacement curves for the cycles obtained after familiarization and preconditioning. Four trials for each measurement occasion were averaged to determine the stiffness value for each subject in one session. Repeatability of glenohumeral joint stiffness measurements for between trials and between two sessions was determined using intraclass correlation values and standard error of the measurements. The mean stiffness value was 1.50 N/mm (±0.40) and 1.52 N/mm (±0.40), respectively. The robotic device for stiffness assessment was reliable for repeated measures of stiffness in one session, and between sessions with ICC equal 0.96 (95% CI 0.93-0.98), and 0.97 (95% CI 0.95-0.99), respectively. The SEM between the trials was in each session 0.08 N/mm. The results of this study provide that our robotic technique for quantifying glenohumeral joint stiffness is precise and reproducible.

Design and Preliminary Evaluation of a Novel Robotic System for Mobilization of Glenohumeral Joint.

Joints mobilization is an essential but subjective treatment in the physical therapy of the patients with joint hypomobility such as frozen shoulder. Recently many instrumented force and displacement indentations have been proposed for assessing and diagnosis of joints stiffness. The devices are not, however, feasible and applicable for use in clinical and therapeutic conditions considering the requirements of the joints mobilization principles in physiotherapy. This paper describes a novel design of a robotic system for mobilization of glenohumeral joint and the preliminary evaluation of mobilization robot in a subject with hypomobile glenohumeral joint. A new mechanism is presented which enables the robotic system to execute the mobilization maneuver in 1 inch linear motion path when it grasps the glenohumeral joint and holds the upper limb situated in the 90 degrees relaxed abduction. It was shown that the mobilization robot can be used effectively and practical for mobilization treatment. Furthermore such a device may be used as a diagnostic and assessing device for evaluating the stage of hypomobility based on Maitland method.

Inter- and intrarater reliability of modified lateral scapular slide test in healthy athletic men.

OBJECTIVE: The reliability of lateral scapular slide test (LSST) at 90 degrees of abduction is controversial; therefore, in order to achieve more reliability it may be necessary to make changes in this particular position. METHODS: Modified lateral scapular slide test (MLSST) was done on thirty male basketball players with two examiners in one session and for the retest with one examiner in the next week. The test was done in 7 positions: arm relaxed at the side (P1), 90 degrees of abduction (P2), 90 degrees of scaption without having a weight in hands (P3), 90 degrees of scaption with having 3 different weights (1, 2, and 4 kg) in hands (P4, P5, and P6, resp.), and 180 degrees of scaption without having a weight in hands (P7). RESULTS: In P1 and P6, the ICC scores indicated the highest level of intrarater reliability. In P2, the ICC scores showed a fair level of intrarater reliability, as the minimum reliability. The maximum and minimum interrater reliability were P1 and P4, respectively. CONCLUSION: Scaption with loading, as a functional position in the overhead athletes, is a reliable positioning and may be replaced with the third position of the traditional LSST.