摘要
Objective To define the biomechanic function of the shoulder in fast throwing movements in baseball pitching. Methods Using NAC high speed video and PIAS LA 555 computer system, overhand pitching movements carried out by 12 healthy Japanese professional baseball pitchers were analyzed in three dimensions. The pitching motion was displayed as stick to stick figures dynamically. Results Pitching motion was a combination of translational and rotational movements. Acceleration and deceleration, being two typical motion patterns, worked sequentially through the anatomic link system from the pivot leg to the pitching hand. During the acceleration phase, the shoulder joint acted as a junction point and a fulcrum, supporting the rotational acceleration motion, shoulder forward flexion and elbow extension. According to the changing glenohumeral angles of the pitching shoulder, shearing force turned into tension force which worked on the anterior shoulder structures and then shifted to the posterior part of the joint. Conclusions In fast throwing motion, the shoulder functions as an important fulcrum to support the pitching arm during the acceleration phase. Avoiding excessive stress and shearing force on the joint components and enhancing coordination of muscle action are important to a successful throwing motion and the prevention of shoulder injury. Familial occurrence of hemangioblastoma of central nervous system $$$$ Zhou Fanmin , Zhang Rong, Ji Yaodong , Xu Qiwu Zhou Liangfu and Shi Yuquan Objective To study the familial occurrence of hemangioblastoma of the central nervous system and to search for an effective way to diagnose and manage the disease. Methods From 1974 to 1993, six patients with hemangioblastoma with family history underwent surgical treatment at our hospital. Computerized tomography (CT) or magnetic resonance imaging (MRI) technique was used for the diagnoses before operation. Results Each patient had more than two relatives with hemangioblastoma. Multiple lesions were found in two of the six familial hemangioblastoma cases. All the patients recovered well after operation. So far, no victims have been discovered in the third generation. Conclusions The high occurrence rate of familial hemangioblastoma cases suggests an involvement of hereditary factors. We need a long follow up study on the descendants of familial hemangioblastoma patients. MRI is of diagnostic value in determining the location and nature of hemangioblastoma in both brain and spinal cord. A thorough examination is necessary for hemangioblastoma patients, and microsurgery is important in removing the tumor.
Objective To define the biomechanic function of the shoulder in fast throwing movements in baseball pitching. Methods Using NAC high speed video and PIAS LA 555 computer system, overhand pitching movements carried out by 12 healthy Japanese professional baseball pitchers were analyzed in three dimensions. The pitching motion was displayed as stick to stick figures dynamically. Results Pitching motion was a combination of translational and rotational movements. Acceleration and deceleration, being two typical motion patterns, worked sequentially through the anatomic link system from the pivot leg to the pitching hand. During the acceleration phase, the shoulder joint acted as a junction point and a fulcrum, supporting the rotational acceleration motion, shoulder forward flexion and elbow extension. According to the changing glenohumeral angles of the pitching shoulder, shearing force turned into tension force which worked on the anterior shoulder structures and then shifted to the posterior part of the joint. Conclusions In fast throwing motion, the shoulder functions as an important fulcrum to support the pitching arm during the acceleration phase. Avoiding excessive stress and shearing force on the joint components and enhancing coordination of muscle action are important to a successful throwing motion and the prevention of shoulder injury. Familial occurrence of hemangioblastoma of central nervous system $$$$ Zhou Fanmin , Zhang Rong, Ji Yaodong , Xu Qiwu Zhou Liangfu and Shi Yuquan Objective To study the familial occurrence of hemangioblastoma of the central nervous system and to search for an effective way to diagnose and manage the disease. Methods From 1974 to 1993, six patients with hemangioblastoma with family history underwent surgical treatment at our hospital. Computerized tomography (CT) or magnetic resonance imaging (MRI) technique was used for the diagnoses before operation. Results Each patient had more than two relatives with hemangioblastoma. Multiple lesions were found in two of the six familial hemangioblastoma cases. All the patients recovered well after operation. So far, no victims have been discovered in the third generation. Conclusions The high occurrence rate of familial hemangioblastoma cases suggests an involvement of hereditary factors. We need a long follow up study on the descendants of familial hemangioblastoma patients. MRI is of diagnostic value in determining the location and nature of hemangioblastoma in both brain and spinal cord. A thorough examination is necessary for hemangioblastoma patients, and microsurgery is important in removing the tumor.
