Neuromuscular and biomechanical strategies of turning in ambulatory individuals post-stroke.
Given that the inter-limb asymmetry and additional balance control are required for turning, stroke subjects spend more time to turn than healthy subjects. Few studies have investigated specific turning-related neuromuscular and biomechanical strategies post-stroke to clarify factors favoring or hindering turning speed toward different directions. The purpose of this study was to compare the speed and lower-limb muscular and kinematic strategies of turning between individuals with stroke and matched controls. Fifteen ambulatory individuals with chronic stroke and 15 matched healthy controls participated in this study. Turning speed during turning along a 0.8-meter radius curved path toward both sides for 5 meters was recorded. Simultaneously, kinematics and muscle activation patterns of lower extremity were measured by the joint angle and electromyography during turning. The slower speed was noted for the turning task in stroke patients when compared to controls. Individuals with stroke have insufficient muscle activation in tibialis anterior and biceps femoris of the affected inner leg, accompanied by reduced standing knee flexion, which disturb turning toward the affected side. The augmented standing knee flexion of unaffected side in stroke patients hindered the function of the outer leg while turning toward the affected side, but assisted the role of the inner leg while turning toward the unaffected side. However, the absence of difference in turning speeds toward the affected and unaffected sides may attribute to the diminished swing phase knee flexion of the affected outer leg. Our findings suggest that there are direction-related strategies in turning for stroke subjects since the inner and outer legs, respectively, have specific roles for standing support and leg swing during turning. Therefore, in addition to turning speed, kinematics and muscular components during turning toward either direction should be considered to improve turning performance as well as to prevent falls in stroke rehabilitation.
Department of Physical Therapy and Assistive Technology, National Yang-Ming University, Taipei 112, Taiwan, Republic of China.
I-Hsuan
IH
Chen
Yea-Ru
YR
Yang
Shih-Jung
SJ
Cheng
Rai-Chi
RC
Chan
Ray-Yau
RY
Wang
D000368:Aged; D000843:Ankle Joint / Q000503:physiopathology; D001696:Biomechanical Phenomena; D004576:Electromyography; D005260:Female; D005269:Femur / Q000502:physiology; D005684:Gait / Q000502:physiology; D020233:Gait Disorders, Neurologic / Q000209:etiology* / Q000503:physiopathology*; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D008124:Locomotion / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology; D020521:Stroke / Q000150:complications* / Q000503:physiopathology*