NeuroRehabilitation - Volume 33, issue 1

Authors: Gorgey, Ashraf S. | Cho, Gilbert M. | Dolbow, David R. | Gater, David R.

Article Type: Research Article

Abstract: Objectives: To investigate the effects of regional thigh composition that result in different responses to current amplitude among individuals with spinal cord injury (SCI) during applications of surface neuromuscular electrical stimulation (NMES) to evoke dynamic leg extension. Design: Cross-sectional. Settings: Academic Settings. Methods: Five males with chronic motor complete SCI completed 3 visits of NMES to determine the current amplitude required to evoke full knee extension. The participants underwent magnetic resonance imaging of both thighs to measure skeletal muscle cross-sectional area (CSA), thigh subcutaneous adipose tissue (SAT) and intramuscular fat (IMF). Applicants were classified …into high (n = 3) and low-responders (n = 2) based on the determined current amplitude. Results: The low-responders required 48–59% greater current amplitude to complete the same task as the high-responders. Low-responders had greater thigh SAT CSA (51–56%) than the high-responders with SCI. After adjusting to whole thigh CSA, IMF CSA was significantly greater in the low- responders; whereas skeletal muscle CSA was lower compared to the high-responders. Conclusion: The findings suggest that thigh SAT and IMF act as insulation against propagation of current during surface NMES applications in individuals with SCI. Show more

Keywords: Spinal cord injury, electrical stimulation, magnetic resonance imaging, subcutaneous adipose tissue, intramuscular fat

DOI: 10.3233/NRE-130941

Citation: NeuroRehabilitation, vol. 33, no. 1, pp. 161-170, 2013

Authors: Suzuki, Toshiaki | Bunno, Yoshibumi | Onigata, Chieko | Tani, Makiko | Uragami, Sayuri

Article Type: Research Article

Abstract: Background: It is unclear whether mental simulation without actual muscle contraction associated with actual motion can increase the excitability of the spinal neural function. Objective: To determine the best method for mental simulation without actual muscle contraction, we analyzed the F-wave of thenar muscles after stimulating the median nerve by motor imagery whilst holding the sensor of a pinch meter between the thumb and index finger and without holding the sensor. Methods: Healthy volunteers (n = 11; mean age, 34 years) participated in this study after providing informed consent. We examined the F-wave of the left …thenar muscles after stimulating the left median nerve at the wrist at rest and under holding and motor imagery conditions. For the motor imagery condition, the subjects were asked to establish 50% maximal voluntary contraction (MVC) of isometric contraction while holding the sensor between the thumb and index finger (motor imagery with the sensor condition) and without holding the sensor on another day (motor imagery without the sensor condition). Results: The persistence and amplitude ratio of F/M during motor imagery with or without the sensor was better than that during relaxation. In particular, this ratio was significantly higher under the with sensor condition than under the without sensor condition. Conclusion: Movement preparation for a motor imagery task involving 50% MVC isometric contraction of the opponens pollicis is important. Show more

Keywords: Motor imagery, F-wave, movement preparation

DOI: 10.3233/NRE-130942

Citation: NeuroRehabilitation, vol. 33, no. 1, pp. 171-176, 2013

Authors: Lee, Na Kyung | Kwon, Jung Won | Son, Sung Min | Kang, Kyung Woo | Kim, Kyoung | Hyun-Nam, Seok

Article Type: Research Article

Abstract: Objective: The major contributors to physical disability after stroke are the negative impairments related to loss of functional ability and muscle strength. The aim of this study was to examine the effects of close kinetic chain (CKC) exercise and open kinetic chain (OKC) exercise on muscle activation of the paretic lower limb and balance in chronic stroke subjects. Methods: Thirty-three patients with chronic stroke of over 6 months were enrolled. They were randomly allocated to three groups: CKC exercise group (n = 11), OKC exercise group (n = 11), and control group (n = 11). CKC and OKC …exercise groups were trained 5 times per week for 6 weeks. The control group maintained routine activities and did not participate in any regular exercise program. All subjects were measured on muscle activation of the paretic lower limb and balance. Results: Muscle activation of rectus femoris (RF) and biceps femoris (BF) was significantly increased in both CKC exercise and OKC exercise groups, compared to the control group. However, muscle activation of gastrocnemius (GC) and tibialis anterior (TA) was significantly increased in only the CKC exercise group. Antero-posterior (A-P) andmedio-lateral (M-L) sway velocities (both with EO and EC) were decreased with the application of CKC exercise. Conclusion: These findings indicate that the CKC exercise can improve lower limb muscle strength, and balance in chronic stroke, and it may carry over into an improvement in functional performance. Show more

Keywords: Close and open kinetic chain exercise, progressive resistance training, stroke

DOI: 10.3233/NRE-130943

Citation: NeuroRehabilitation, vol. 33, no. 1, pp. 177-183, 2013