A Biomechanical Analysis of Strength and Motion Following Total Shoulder Arthroplasty

Background: The primary goal of total shoulder arthroplasty (TSA) has traditionally been pain relief and motion improvement. The literature contains multiple studies that have documented the restoration of motion and consistent pain relief following the procedure. However; there has been little attention placed on strength following TSA. Therefore; the purpose of this study was to determine in an objective manner whether strength and motion improve with shoulder arthroplasty and over what time course this may occur. aterials and Methods: Between April 2002 and January 2004; 15 patients who underwent TSA for osteoarthritis had biomechanical strength testing preoperatively; at 6 and 12 months postoperatively. The mean age at the time of TSA was 66 years (range; 52-82). None of the patients had full thickness rotator cuff tears at the time of surgery. Peak forces for shoulder flexion; extension; abduction; internal rotation and external rotation strength were recorded. In addition; patients had shoulder range of motion measurements performed.Findings: Range of motion improved significantly with TSA from preoperative to 6 months postoperative: flexion 104o to 147o ( P = 0.0034); abduction 86o to 145o ( P = 0.0001); internal rotation 43o to 54o ( P = 0.0475) and external rotation 25o to 50o ( P = 0.0008). There was minimal improvement in range of motion from 6 to 12 months. In contrast; there continued to be improvements in strength from the 6 month to the 12 month postoperative time frame: extension 18.3 kg to 22.4 kg ( P = 0.006); abduction 11.3 kg to 12.8 kg (0.0474) and external rotation 8.8 kg to 10.1 kg ( P = 0.016). Despite these improvements; compared to normative values; there continued to be relative weakness of the shoulder following TSA.Interpretation: The data from this study suggest that recovery of strength and motion follow different time frames after TSA. The results of this study may allow the surgeon to more accurately discuss with the patient over what time course strength and motion may return. In addition; this study raises important questions in regard to the current rehabilitation program used after shoulder arthroplasty and whether development of new protocols may improve the functional outcome from surgery

Range of Motion in Selected Joints of Diabetic and Non-Diabetic Subjects

The purpose of the study was to compare the mobility of selected joints of the limbs in diabetic and non-diabetics subjects. One hundred subjects comprising of 50 volunteer diabetics and 50 volunteer non-diabetics subjects participated in this study. The range of motion of the shoulder; elbow; wrist; fingers; hip and knee joins were measured using a double armed simple goniometer and recorded in degrees. The outcome of this study revealed that there was a significant difference between joint mobility in the diabetic and non-diabetic subjects for all the joints range measured except the knee and elbow joints. There was also a low and positive correlation between duration of diabetes and frequency of finger deformities. No significant difference was found between joint mobility of male and female diabetics subjects. It was concluded that reduced range of motion of some joints especially of the wrist and hand could set in as a complication diabetics conditions