A Kinematic Analysis of Grenade Throwing

Hung-Maan Lee ； Wu-Chou Chen

《Journal of Medical Sciences》 24卷5期 (2004/10) Pp. 243-248

並列摘要

Background: In military action, the grenade is a useful weapon for use at a distance against the enemy. When training soldiers to throw grenade, various injuries occur during practice. Therefore, it is necessary to understand the mechanism of the throwing process, in order to avoid injuries effectively. Methods: This study used 2 high-speed cameras (120 Hz) to collect kinematic throwing data from 100 recruits and 30 squad leaders. Each subject was allowed 3 throws and the data collected was smoothed and calculated through a PEAK Motus system. SPSS 10 was used for statistical analysis (P＜0.05). Interviews and questionnaires were also used to gather in-depth information. Results: Results revealed that: 1. Compared with recruits, squad leaders had a higher number of throws and a higher injury ratio. 2. Promoting first aid techniques and requesting sufferers to accept treatment were necessary as only half of the injured subjects accepted proper medical care. 3. Compared with pitching, recruits had shorter strides and stood more erect at grenade release when projecting the grenade to a distance. 4. The forward trunk tilt angle and shoulder extension angle in the throwing phase, the shoulder angle at grenade release and the forward trunk tilt angle in the follow-through were significantly greater in squad leaders. 5. Squad leaders exhibited a better Open Kinetic Chain sequence in the upper arm, forearm and wrist linkage. 6. The kinetic energy percentage was greater at the shoulder and smaller at the elbow for the squad leaders. 7. The relationship between increased throwing experience and higher injury ratio indicated that the number of throws is the main source of injury. 8. In order to comprehend the association between throwing technique and injury clearly, further studies should integrating kinetic analysis and electromyography of specific muscle.

並列關鍵字

grenade ； kinetic chain ； kinetic energy ； throwing