Effects of hand support on muscle responses during tilting perturbations in young and old adults

• Main Authors: Ching-Yi Chu, 朱靜宜
• Other Authors: Ming-Hsia Hu
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/14531706065027305651

碩士 === 國立臺灣大學 === 物理治療學研究所 === 91 === Purpose：The aim of the study was to compare the effects of hand support on muscle responses under tilting perturbation in young and old adults. Methods：This is a cross-sectional study design. Thirty young subjects (15 females and 15 mans, 24.00±2.60 y/o) and thirty old subjects participated in the study. Each subject received postural muscle response test with tilting perturbations, sensory organization test(SOT) and clinical evaluation. Postural responses were tested using the Smart Balance Master system (NeuroCom Int Inc, Oregon, USA) with eight channels electromyography (EMG). The stimuli were 4∘upward or downward platform tilts at 50∘/s. Four conditions were tested: up tilt with cane、up tilt without cane、down tilt with cane、down tilt without cane).Five trials were given for each of the four conditions. EMG activities of bilateral tibialis anterior, medial gastrocnemius, rectus spinal and the triceps of right arm were recorded for further analysis. The parameters included: Sensory integration test. The SOT exposes the subjects to the six conditions(support surface and visual surround are fixed, and subject stands with eyes open and closed, eyes open and with the surround fixed, and eyes open and the visual surround sway referenced). The clinical evaluation are the strenth of the bilateral quadriceps, tibialis anterior, medial gastrocnemius and triceps, wrist flexor, wrist extensor of the right arm, the range of motion (ROM) of the hip joint, knee joint, and ankle joint ,the light touch and proprioception of hand , foot. Results：The results showed (1) The older groups had significantly longer onset latency in the gastrocnemius, smaller integrated EMG in the gastrocnemius following upward tilting perturbation. The older groups had significantly longer onset latency in the tibialis anterior, rectus spinal, greater integrated EMG in the rectus spinal following downward tilting perturbation. (2) The hand support had significantly shorter onset latency in the tibialis anterior, rectus spinal, right triceps, smaller integrated EMG in the tibialis anterior, gastrocnemius following upward tilting perturbation. When hand is supported subjects had significantly longer onset latency in the rectus spinal, smaller integrated EMG in the gastrocnemius following downward tilting perturbation. When without hand is supported subjects had significantly smaller integrated EMG in the gastrocnemius following downward tilting perturbation. (3) The left side had significantly shorter longer latency in the gastrocnemius following upward tilting perturbation. The left side had significantly shorter smaller integrated EMG in the tibialis anterior, gastrocnemius following downward tilting perturbation. The older groups had significantly lower equilibrium scores(p＜.015), poor of % max stability in support surface and visual surround fixed and eyes open(p＜.002) and close(p＜.0001), eye open and with the visual surround fixed and support surface sway-referenced(p＜0.014), eyes open and the visual and support surface sway-referenced(p＜0.0001), more falls numbers.(p＜0.0001), small strengh in wrist extensor of right arm(p＜0.0001), wrist flexor of right arm(p＜0.0001), triceps of right arm(p＜0.033), tibialis anterior of right leg,(p＜0.033), tibialis anterior of left leg(p＜0.0001), medial gastrocnemius of right leg(p＜0.004), medial gastrocnemius of rleft leg(p＜0.0001), quadriceps of right leg(p＜0.002), qudriceps of left leg(p＜0.0001),small ROM in hip flexion(p＜0.0001)、knee flexion of left side(p＜0.006)、ankle dorsiflexion of left side(p＜0.007)、ankle plantar flexion of right side(p＜0.0001). Conclusion: Our fining suggested that hand support may improve posture response in elderly during tilting perturbation. When designing balance training programs, therapists should consider the elderly’s postural responses, and level of functional stability.