Development and evaluation of gas-pressurized elastic sleeves for extravehicular activity.
BACKGROUND
In space, mobility of the current extravehicular activity space suit is limited due to the pressure differential between the inside and outside of the suit. We have previously demonstrated that an elastic glove increased mobility when compared with a non-elastic glove such as that found in the current suit. Extending this work, we hypothesized that an elastic sleeve would also have more mobility compared to a non-elastic sleeve, but a partially elastic sleeve, consisting of elastic joints sewn to non-elastic parts in low mobility areas, might generate similar mobility to a wholly elastic sleeve.


METHODS
The right arms of 10 volunteers were studied with wholly elastic, partially elastic, and non-elastic sleeves in a chamber pressure of -220 mmHg. Range of motion (ROM) of the wrist and electromyography (EMG) of the flexor carpi radialis muscle and the biceps brachii muscle during wrist and elbow flexion were measured.


RESULTS
ROM of the wrist was similar among all the sleeves. However, EMG amplitudes during wrist flexion with both elastic sleeves were significantly smaller than that with the non-elastic sleeve. EMG amplitudes during 90 degrees of elbow flexion were also significantly smaller in both elastic sleeves. However, no significant difference in EMG amplitudes was observed between the two elastic sleeves (0.53 +/- 0.06, 0.56 +/- 0.07, 1.14 +/- 0.10 V for wholly elastic, partially elastic, and non-elastic sleeves, respectively).


CONCLUSIONS
The mobility of elastic sleeves is better than that of a non-elastic sleeve. Elasticity over the joints is important; however the elasticity of the other parts does not appear to affect mobility.
Tanaka
Kunihiko
K
Gifu University, Graduate School of Medicine, Department of Physiology, Gifu, Japan. kutanaka@gifu-u.ac.jp
Tohnan
Momoka
M
Abe
Chikara
C
Iwata
Chihiro
C
Yamagata
Kenji
K
Tanaka
Masao
M
Tanaka
Nobuyuki
N
Morita
Hironobu
H
D000328:Adult; D004548:Elasticity; D004576:Electromyography; D004867:Equipment Design; D018478:Extravehicular Activity; D005260:Female; D018737:Hand Strength; D006801:Humans; D008297:Male; D016059:Range of Motion, Articular; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply; D012881:Skin Temperature; D019442:Space Suits; D014955:Wrist Joint / Q000502:physiology; D055815:Young Adult