Repetitive overhead throwing may result in overuse injuries and a change in the pitching mechanics of a baseball pitcher. Accordingly, the purpose of this study is to quantify the changes in the muscle strength and pitching motion kinematics in the late-innings stage of a baseball game. Sixteen healthy baseball pitchers (16.77 ± 0.73 years) recruited from a high school, which won the National High School Baseball Championship in Taiwan in 2011; each performed 100 pitches in a bullpen throwing session. Isometric muscle strength measurements and joint kinematic data were obtained before and after the throwing session. The mean Borg's Rating of Perceived Exertion index was found to have a value of 14.14, indicating a medium-to-large degree of perceived tiredness. The results showed that the ball velocity and horizontal abduction angle decreased significantly as the pitchers became tired. Moreover, the upper torso forward tilt and knee flexion angle both increased significantly at the moment of ball release. Finally, the muscle strength of the upper extremity remained decreased 2 days after the bullpen throwing session. Overall, the results suggest that an adequate amount of rest and specific strengthening programs for the shoulder external rotator, shoulder internal rotator, shoulder flexor, shoulder extensor, shoulder adductor, and shoulder abductor muscles are recommended to the coaches and for adolescent baseball pitchers. In addition, the changes in pitching mechanics noted in this study should be carefully monitored during the course of a baseball game to minimize the risk for overuse injuries.

In adolescents, neurovascular injury, especially ulnar nerve injury, is rare with fracture of the distal radius. We present a 14-year-old boy who sustained fracture of the distal radius in his right wrist, who also had symptoms of ulnar nerve injury. Close reduction with percutaneous pinning and cast to fix the distal radius fracture was done immediately. Then, we decided to observe the recovery of the nerve injury without providing any emergent nerve exploration. Bone union was achieved after 8 weeks of fixation, and the function of the ulnar nerve was restored completely after 16 weeks of observation. The possibility of ulnar nerve injury should be considered following fracture of the distal aspect of the radius, and we recommend observing the recovery of nerve injury, with no need for emergent nerve exploration.

The bench press is one of the most popular weight training open-kinetic chain exercise (OKCE) for the upper extremity. Reviewing the literature, there is a very little research regarding the biomechanical analysis of the OKCE of the upper extremity. The purpose of this study is to develop an OKCE testing model of the upper extremity by using the 3D Motion Analysis System. Furthermore, elbow joint loading of two different hand grip position during the bench-press exercise will be investigated. Thirteen male students volunteered for the study. Their average age was 26.1 years, with an average height of 170.6 cm, and an average weight of 70.3 kg. With both hands in neutral position, each subject was asked to perform bench-press type 1 (normal shoulder width), and bench-press type 2 (150% shoulder width). During the type 2 bench-press exercise, there is a significant increase in anterior–posterior and medial–lateral force on the elbow joint loading than the type 1 bench-press exercise. The valgus–varus, flexion–extension moment, and supination–pronation moment of the type 2 bench-press exercise are also greater than the type 1 bench-press exercise. As shown in this study, keeping the distance of both hand grips as shoulder width may reduce the elbow joint loading during bench-press exercise. These data will provide helpful information in clinical rehabilitation and treatment of the upper-extremity injures.

Osteoarthritis (OA) encompassed a large and heterogeneous number of disorders affecting joints and bones, which culminate in a joint failure. In general, OA can be defined as a degenerative disease characterized by biomechanical and architectural deteriorations of the articular cartilage. After the age of 60 years, more than 80% of the people have radiological signs of OA in the knee, and 20% of the people suffer from pain and movement limitations. Currently used pharmacologic treatments, including acetaminophen and nonsteroidal anti-inflammatory drugs, do not slow or reverse the degenerative process in osteoarthritis. Glucosamine, a chondro-protective substance, has recently received a great deal of attention from the public as a potential treatment of osteoarthritis, prompting healthcare professionals to investigate its clinical usefulness and potential for adverse effects. Improvement in the symptoms of osteoarthritis associated with the use of glucosamine has been observed in clinical trials. The purpose of this study was to better define the efficacy of these chondro-protective agents in treating OA. The short term and long term results were evaluated with pain score, and the most importantly, we proposed to objectively evaluate the muscle strength, and the joint motion with gait and sit-to-stand analysis. These data will warrant a better understanding of the efficacy of these chondro-protective agents in treating osteoarthritic patients.