Effective Frequency of External Feedback for Increasing the Percentage of Body Weight Loading on the Affected Leg of Hemiplegic Patients

편마비환자의 환측하지 체중부하율 향상을 위한 효과적인 외적 되먹임 빈도

  • Noh, Mi-He (Dept. of Rehabilitation, College of Health Science, Yonsei University) ;
  • Yi, Chung-Hwi (Dept. of Rehabilitation, College of Health Science, Yonsei University Institute of Health Science, Yonsei University) ;
  • Cho, Sang-Hyun (Dept. of Rehabilitation, College of Health Science, Yonsei University Institute of Health Science, Yonsei University) ;
  • Kim, Tae-Ue (Dept. of Medical Pathology, College of Health Science, Yonsei University Institute of Health Science, Yonsei University)
  • 노미혜 (연세대학교 보건과학대학 재활학과) ;
  • 이충휘 (연세대학교 보건과학대학 재활학과 및 보건과학연구소) ;
  • 조상현 (연세대학교 보건과학대학 재활학과 및 보건과학연구소) ;
  • 김태우 (연세대학교 보건과학대학 임상병리학과 및 보건과학연구소)
  • Published : 1998.09.19

Abstract

In motor learning, the relative frequency of external feedback is the proportion of external feedback presentations divided by the total number of practice trials. In earlier studies, increasing the percentage of body weight loading on the affected leg of hemiplegic patients, external feedback was continuously produced as the patient attempted to perform a movement. This feedback was produced to enhance the learning effect. However, recent studies in nondisabled populations have suggested that compared with 100% relative frequency conditions, practice with lower relative frequencies is more effective. My study compared the effect of 100% relative frequency conditions with 67% relative frequency conditions to determine what effect they exerted on motor learning for increasing the percentage of body weight loading on the affected lower limbs of patients with hemiplegia. Twenty-four hemiplegic patients were randomly assigned to one of two experimental groups. Each group practiced weight transfer motor learning on a machine. During practice, visual feedback was offered to all subjects. The experiment was carried out with full visual feedback for patients in group one but only 67% visual feedback for patients in group two. The percentage of loading on the affected leg was recorded four times: before learning (baseline value), immediately after learning, 30 minutes after learning, 24 hours after learning. The results were as follows: 1. In the 100% visual feedback group, the percentage of loading on the affected leg increased significantly in all three testing modes over the baseline value. 2. In the 67% visual feedback group, the percentage of loading on the affected leg increased significantly in all three measurements. 3. Immediately after learning, the learning effect was not significantly different between the two groups, but was significantly greater after both the 30 minutes delay and the 24 hours period. These results suggest that the 33% reduction in the provision of visual feedback may enhance the learning effect of increasing the percentage of body weight loading on the affected leg in patients with hemiplegia.

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