Standing Balance Characteristics Of Human With A History Of Ankle Injury

PURPOSE: Plantar baroreceptors were used to collect plantar pressure parameters in four standing positions to study the standing balance characteristics of people with a history of ankle injury. METHODS: The Zebris FDM-System was used to collect the plantar pressure indexes(COP,95%confidence ellipse area, COP path length, COP average velocity, Length of minor/major axis, Percentage of backfoot average forces, angle btw Y & major axis, Deviation Y/X) of 49 subjects (20.9 ± 0.91) in four standing positions(Stand with feet apart and eyes closed/opened, SAEC/SAEO, stand with feet together and eyes closed/opened, STEC/STEO). The data were analyzed by mathematical statistics for the independent sample T-test (p < 0.05). RESULTS: The percentages of left/right hind foot pressure in SAEC(58.67 ± 15.82,41.33 ± 15.82),SAEO(59.29 ± 20.11,40.71 ± 20.11),STEC(59.92 ± 15.85, 40.08 ± 15.85) and STEO(60.51 ± 19.90, 39.49 ± 19.90) were significantly different (P < 0.01).There were significant differences in the COP path length (100.39 ± 48.00 and 120.57 ± 52.88), COP average velocity(7.08 ± 3.52 and 8.59 ± 3.77) and the angle btw Y and major axis(69.91 ± 24.86 and 79.51 ± 14.86) between SAEO and SAEC (p < 0.01).The COP average velocity between the SAEO (7.08 ± 3.52) and STEO (11.94 ± 3.94),SAEC (8.59 ± 3.77) and STEC (18.04 ± 5.41), STEO (11.94 ± 3.94) and STEC (18.04 ± 5.41),the 95% confidence ellipse area between the SAEO (156.18 ± 198.28) and STEO (459.96 ± 253.71),SAEC (150.73 ± 126.60) and STEC (737.10 ± 418.45), STEO (459.96 ± 253.71) and STEC (737.10 ± 418.45), the length of minor axis between the SAEO (7.79 ± 4.45) and STEO (18.60 ± 5.13),SAEC (7.81 ± 4.09) and STEC (23.13 ± 6.74), STEO (18.60 ± 5.13) and STEC (23.13 ± 6.74),and the angle btw Y & major axis between the SAEO (69.91 ± 24.86) and STEO (50.37 ± 29.13), the SAEC(79.51 ± 14.86) and STEC (31.76 ± 23.42), the STEO (50.37 ± 29.13) and STEC (31.76 ± 23.42),respectively all of which were highly significant difference (P < 0.01). CONCLUSIONS: People with ankle injury history could increase the risk of recurrent injuries. The input of visual information has positive effect on stability of standing with feet together, and the expansion of the support area has positive influence on standing stability. The sway of subjects appears more often in the front-rear direction than the left-right direction.