Reaction times (RTs) of nine normal subjects and 11 amputees with prosthetic limbs were examined in standing posture and during stepping movement. There were significant differences of RTs between standing and stepping, and between the phases of the stepping cycle in both the normal subjects and the BK or AK amputees with prosthetic limbs. The attentional demand during stepping movement and the applicability of probe RT procedure to assess prosthetic limb were briefly discussed.

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Electromyographic reaction times (EMG-RTs) of the right knee extension were examined in eight normal subjects and eight patients with paraparesis under three conditions; during passive knee flexion (PFLX), passive extension (PEXT) and no passive movements (STAT). EMG-RTs of the three conditions were not significantly different between the normal and the patient group. A two-way analysis of variance (condition x group) showed that the main effect of condition was significant, but that of group and the interaction were not. Both in the normal and the patient group the shortest EMG-RTs of all was obtained in PEXT, followed by that of STAT and PFLX. Effect of passive movements on EMG-RTs in the patients whose position sense of the knee and muscle strength of the knee extension were within normal range did not vary with the abnormality of tactile sense and/or myotatic reflexes. The results indicated that activities of the pyramidal tract neurons in carrying out a movement were directy influenced by kinesthetic information of the moving limb. ---passive movement; reaction time; paraparesis By measuring electromyographic (EMG) activities of a prime mover muscle in simple reaction time (RT) experiments, several variables influencing the initiation of voluntary movements have been investigated; preparatory interval (Botwinick and Thompson 1966), preliminary muscle tension (Schmidt and Stull 1970), movement pattern (Nakamura and Saito 1974) and posture (Nakamura 1976/77;Taniguchi et al. 1980). These variables are deliberately manipulated during therapeutic exercises in rehabilitation medicine. Passive and active assistive exercises are often prescribed as the first regimen for a therapeutic measure. Passive movements are recognized as constituting a potent source of variation in EMG-RTs. Compared to a static condition, EMG-RTs of the biceps brachii muscle were faster during passive flexion of the elbow and slower during passive extension of the elbow (Nakamura et al. 1982). Concerning those physiological mechanisms, it was suggested that kinesthetic information about the passive

Reaction times (RTs) of vocalization were examined for 20 normal subjects under two conditions, standing and walking. The RT during walking was not related to the phases of walking cycle. The difference in RTs (ΔRT) was obtained by subtracting RT for standing from that of walking. The correlation coefficient between RT for standing and ΔRT was significant and negative. ΔRTs for subjects with fast RT for standing were positive, whereas those with slow RT were negative. Assuming that the arousal level when standing is different between the faster and slower reactors, the probe-RT during walking would reflect not only the extra-attentional demands of walking but also the shift in arousal.

[Purpose] To clarify the relationships of functional status at the time of discharge with the recovery prognoses of instrumental activities of daily living (IADL) and life-space in the early stage after discharge to home of elderly orthopedic patients. [Subjects and Methods] The subjects were 32 elderly patients (average age 77.3 years) who were capable of cane gait before hospitalization and were discharged from hospital to their homes. We measured their IADL and life-space monthly for three months after discharge, and examined their relationships with functional status at the time of discharge using Spearman's correlation analysis and stepwise multiple regression analysis. [Results] Cognitive function showed significant relationships with IADL at all the time points after discharge; and the Timed Up and Go test and 5-m walking time showed significant relationships with life-space at 1 and 3 months after discharge. [Conclusion] We clarified the relationships of the recovery prognoses of IADL and life-space with cognitive and motor functions in the early stage after discharge, and the possibility of their prediction.