Research article - (2013)12, 409 - 413
The Effect of Landing Surface on the Plantar Kinetics of Chinese Paratroopers Using Half-Squat Landing
Yi Li1, Ji Wu,1, Chao Zheng1, Rong Rong Huang1, Yuhong Na2, Fan Yang3, Zengshun Wang1, Di Wu1
1Air Force General Hospital, Beijing, China
2Harbin Institute of Technology, Harbin, China
3China National Institute of Standardization, Beijing, China

Ji Wu
✉ The Department of Orthopedics, Air Force General Hospital, No.30 Fucheng Road Haidian District, Beijing 100142, China
Email: bjwuji@yahoo.com.cn
Received: 17-01-2013 -- Accepted: 04-04-2013
Published (online): 01-09-2013

ABSTRACT

The objective of the study was to determine the effect of landing surface on plantar kinetics during a half-squat landing. Twenty male elite paratroopers with formal parachute landing training and over 2 years of parachute jumping experience were recruited. The subjects wore parachuting boots in which pressure sensing insoles were placed. Each subject was instructed to jump off a platform with a height of 60 cm, and land on either a hard or soft surface in a half-squat posture. Outcome measures were maximal plantar pressure, time to maximal plantar pressure (T-MPP), and pressure-time integral (PTI) upon landing on 10 plantar regions. Compared to a soft surface, hard surface produced higher maximal plantar pressure in the 1st to 4th metatarsal and mid-foot regions, but lower maximal plantar pressure in the 5th metatarsal region. Shorter T- MPP was found during hard surface landing in the 1st and 2nd metatarsal and medial rear foot. Landing on a hard surface landing resulted in a lower PTI than a soft surface in the 1stphalangeal region. For Chinese paratroopers, specific foot prosthesis should be designed to protect the1st to 4thmetatarsal region for hard surface landing, and the 1stphalangeal and 5thmetatarsal region for soft surface landing.

Key words: Half-squat landing, plantar kinetics, plantar pressure, surface reaction force, pressure time integral

Key Points
  • Understanding plantar kinetics during the half-squat landing used by Chinese paratroopers can assist in the design of protective footwear.
  • Compared to landing on a soft surface, a hard surface produced higher maximal plantar pressure in the 1 to 4 metatarsal and mid-foot regions, but lower maximal plantar pressure in the 5 metatarsal region.
  • A shorter time to maximal plantar pressure was found during a hard surface landing in the 1 and 2 metatarsals and medial rear foot.
  • Landing on a hard surface resulted in a lower pressure-time integral than landing on a soft surface in the 1 phalangeal region.
  • For Chinese paratroopers, specific foot prosthesis should be designed to protect the 1 to 4 metatarsal region for a hard surface landing, and the 1 phalangeal and 5 metatarsal region for a soft surface landing.








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