RESUMEN
ObjectiveTo investigate the immediate effect of wearing a soft ankle brace on dynamic and static balance function and biomechanics of affected lower limbs during walking in chronic ankle instability (CAI) patients. MethodsFrom January to August, 2021, 40 CAI patients from Musculoskeletal Rehabilitation Center, Beijing Rehabilitation Hospital, Capital Medical University were measured dynamic and static balance indexes with Zebris FDM-System and Y balance test, before and after wearing a soft ankle brace; while the kinetics indexes and surface electromyography of the affected lower extremities during walking were collected with Zebris FDM-System and a surface electromyography telemeter simultaneously. ResultsThe velocity and area of center of pressure reduced in both open and closed eye modes (|t| > 2.876, P < 0.01), the Y-balance scores increased in all the directions (|t| > 21.212, P < 0.001) after wearing brace; while the peak pressures and impulses increased in the midfoot and medial forefoot regions (|t| > 2.057, P < 0.05), and decreased in the lateral heel, lateral forefoot and toe regions (|t| > 2.464, P < 0.05), and the root mean square of surface electromyography increased in the tibialis anterior and lateral gastrocnemius (|t| > 2.159, P < 0.05) during walking. ConclusionWearing soft brace can immediately improve dynamic and static balance of CAI patients, and optimize plantar kinetic distribution and enhance activation of the anterior tibial and the lateral head of gastrocnemius of the affected limb during walking, to improve motor control of CAI patients.
RESUMEN
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(st)phalangeal region. For Chinese paratroopers, specific foot prosthesis should be designed to protect the1(st) to 4(th)metatarsal region for hard surface landing, and the 1(st)phalangeal and 5(th)metatarsal region for soft surface landing. Key PointsUnderstanding 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.