The Effect of Landing Surface on the Plantar Kinetics of Chinese Paratroopers Using Half-Squat Landing

摘要

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 1^st to 4^th metatarsal and mid-foot regions, but lower maximal plantar pressure in the 5^th metatarsal region. Shorter T- MPP was found during hard surface landing in the 1^st and 2^nd metatarsal and medial rear foot. Landing on a hard surface landing resulted in a lower PTI than a soft surface in the 1^stphalangeal region. For Chinese paratroopers, specific foot prosthesis should be designed to protect the1^st to 4^thmetatarsal region for hard surface landing, and the 1^stphalangeal and 5^thmetatarsal region for soft surface landing.Key Points class="unordered" style="list-style-type:disc">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^st to 4^th metatarsal and mid-foot regions, but lower maximal plantar pressure in the 5^th metatarsal region.A shorter time to maximal plantar pressure was found during a hard surface landing in the 1^st and 2^nd 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^st phalangeal region.For Chinese paratroopers, specific foot prosthesis should be designed to protect the 1^st to 4^th metatarsal region for a hard surface landing, and the 1^st phalangeal and 5^th metatarsal region for a soft surface landing.