Musculoskeletal biomechanics simulation and EMG analysis of shoulder muscles for archery sport

In practice the behavior of the Bow-Arrow-Archer system termed 'interior ballistics' and the arrow in flight termed ‘exterior ballistics' are complicated. In order to understand the mechanics of archery computer models are required. The musculoskeletal simulation is becoming a popular method in the research field of biomechanics to estimate muscle activity from body motion. The objective of this study is to conduct biomechanically correct musculoskeletal transient response under archery dynamic loading. This simulation aims to find the movement patterns in working postures, amount of muscle activity, individual muscle forces and the amount of glenohumeral and sternoclavicular joint reactions established during archery performance. The work presented discusses the anatomical body arrangements and conducts bio mechanically correct simulation. Initially a C3D file was generated with makers specified on the upper body to generate the archery motion. The C3D file contains the synchronized 3D and analog data. It also helps in standardizing the interchange of information. The C3D file is imported into human mannequin model which provides a platform for performing musculoskeletal simulation. Repetitive use of shoulder joint for archery performance results in micro traumas of shoulder joint. Overuse of the shoulder which, through repetitive harmful movements, can bring about micro traumatic lesions of the rotator. Knowledge on the position of the arm and forearm during injury, the degree of muscle contraction or relaxation and the direction and momentum of the archer helps in determining the severity of injury. Musculoskeletal simulation gives additional information about mechanism and force of the injury, thus helping in describing the pathoanatomy. We use Electromyography (EMG) which provides easy access to physiological processes that cause the muscle to generate force, produce movement and accomplish the countless functions that allow us to interact with the world around us. The muscle interactions are further co-related with the simulation results. The response of the accessory muscle and primary muscle forces during archery draw back are examined by EMG- driven biomechanical models. By simulating the model, one can analyze the causes for the most common shoulder pain observed in archers. For each analysis, the system stores the maximum stress of muscle at any point of the movement. The simulation estimates the optimum parameters to eliminate stress overloading on the muscles and investigates muscle efforts and joint forces depending on posture