Effect of Visual input on stretch responses of ankle muscles during movements to absorb impact.
- VernacularTitle:衝撃緩衝動作時の足関節筋群の反射活動に及ぼす視覚入力の影響
- Author:
KIYOTAKA KAMIBAYASHI
;
CHIGAYA TADANO
;
MASAE YONA
;
HIROYUKI SEKI
;
MASUO MURO
- Publication Type:Journal Article
- Keywords:
Motor control;
Preactivation;
Stretch reflex;
Reflex gain;
Sensory input
- From:Japanese Journal of Physical Fitness and Sports Medicine
2002;51(5):447-456
- CountryJapan
- Language:Japanese
-
Abstract:
The purpose of this study was to examine the effect of the different visual and vestibular inputs on EMG response of ankle muscles during movement to absorb impact in sliding down a slope. Thereby, our research focused on the relationship between preactivation (PA) in central program and stretch reflex induced by dorsiflexion immediately after impact. The subjects were nine healthy males. Movements were conducted using a special sliding apparatus. Conditions included sliding down a lower 15°slope with eyes open (Low) and with eyes closed (Low-Closed), and a higher 20°slope with eyes open (High) . PA prior to impact indicated the co-contraction of the medial gastrocnemius (MG) and tibialis anterior (TA) . PA levels in those muscles were significantly higher during High than during Low-Closed (p<0.05) . In contrast, PA of the coleus (Sol) was low in all test conditions. After impact, however, the stretch reflex of Sol during Low-Closed was greater than other test conditions. Because muscle stretch velocities and PA levels of Sol among all test conditions remained unchanged, these results suggest that different visual inputs could change the response of stretch reflex by modulations in reflex gain.
