Changes in Shoulder Muscle Activities Depending on Static and Dynamic Body Positions during Shoulder External Rotation Exercises Using Kinetic Chain Concept / 대한스포츠의학회지

Purpose@#We aimed to evaluate shoulder muscle activities during shoulder external rotation exercises using an elastic band with the arm at the side or at 90° of abduction in static and dynamic body positions. @*Methods@#In 2017, a total of 19 right-handed male subjects were included in this study. Surface electromyography signals were recorded from the anterior deltoid, middle deltoid, upper trapezius, lower trapezius, serratus anterior, and infraspinatus muscles. The subjects underwent maximal voluntary isometric contraction testing of each muscle in the W position or 90/90 position. Subjects performed the exercise in the sitting, static squat, static rotational squat, dynamic squat to standing (DSS), and dynamic squat to standing and trunk rotation (DSSR) positions. @*Results@#The main finding of this study was that shoulder external rotation exercises in the DSSR position were effective in reducing shoulder muscle activities except in the serratus anterior compared with static rotational squat position. @*Conclusion@#DSSR enabled effective control of scapular motion with less shoulder muscle activation. Therefore, the kinetic chain exercises incorporated with lower extremity, hip, or trunk would be beneficial for shoulder muscle exercises, which is required for patients with weak periscapular muscles, in whom the lower trapezius activities were found to be frequently decreased.

Supramalleolar Distal Tibiofibular Osteotomy for Medial Ankle Osteoarthritis: Current Concepts

The supramalleolar osteotomy is a joint-preserving surgical procedure. It is a very good treatment option for the asymmetric varus ankle and medial compartment osteoarthritis. The primary objective of the procedure is to shift medial concentration of stress toward the lateral intact articular cartilage to redistribute the joint loads during ambulation. Several studies have shown that deformities of the ankle result in uneven load distribution in the ankle joint, which eventually leads to articular cartilage degeneration. Since the lateral articular cartilage is intact, joint-sacrificing procedures such as total ankle replacement or ankle arthrodesis are not the most appropriate treatment choices for medial compartment arthritis. Results of supramalleolar osteotomies are very promising in terms of functional outcome and pain relief. In younger patients with medial compartment varus ankle osteoarthritis or even with a normal tibial anterior surface angle, supramalleolar osteotomies can be performed to realign the ankle to promote regeneration of the asymmetrically damaged cartilage. In this review article, we will discuss the indications, complications, surgical techniques, and outcomes of the supramalleolar osteotomy reported in the current literature.