Parachute Landing Fall Characteristics at Three Realistic Vertical Descent Velocities
Abstract:Whitting JW, Steele JR, Jaffrey MA, Munro BJ. Parachute landing fall characteristics at three realistic vertical descent velocities. Aviat Space Environ Med 2007; 78:1135–42.
Introduction: Although parachute landing injuries are thought to be due in part to a lack of exposure of trainees to realistic descent velocities during parachute landing fall (PLF) training, no research has systematically investigated whether PLF technique is affected by different vertical descent conditions, with standardized and realistic conditions of horizontal drift. This study was designed to determine the effects of variations in vertical descent velocity on PLF technique. Methods: Kinematic, ground reaction force, and electromyographic data were collected and analyzed for 20 paratroopers while they performed parachute landings, using a custom-designed monorail apparatus, with a constant horizontal drift velocity (2.3 m · s−1) and at three realistic vertical descent velocities: slow (2.1 m · s−1), medium (3.3 m · s−1), and fast (4.6 m · s−1). Results: Most biomechanical variables characterizing PLF technique were significantly affected by descent velocity. For example, at the fast velocity, the subjects impacted the ground with 123° of plantar flexion and generated ground reaction forces averaging 13.7 times body weight, compared to 106° and 6.1 body weight, respectively, at the slow velocity. Furthermore, the subjects activated their antigravity extensor muscles earlier during the fast velocity condition to eccentrically control the impact absorption. Discussion: As vertical descent rates increased, the paratroopers displayed a significantly different strategy when performing the PLF. It is therefore recommended that PLF training programs include ground training activities with realistic vertical descent velocities to better prepare trainees to withstand the impact forces associated with initial aerial descents onto the Drop Zone and, ultimately, minimize the potential for injury.
Document Type: Research Article
Publication date: 2007-12-01
More about this publication?
- The peer-reviewed monthly journal, Aviation, Space, and Environmental Medicine (ASEM) provides contact with physicians, life scientists, bioengineers, and medical specialists working in both basic medical research and in its clinical applications. It is the most used and cited journal in its field. ASEM is distributed to more than 80 nations.
To access volumes 86 to present, please click here.
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Information for Advertisers
- Submit Articles
- Ingenta Connect is not responsible for the content or availability of external websites