scholarly journals Motor Control of Quadriceps Femoris during Isometric Knee Flexion Contraction

2017 ◽  
Vol 32 (1) ◽  
pp. 51-55
Author(s):  
Takahiro UCHIDA ◽  
Toshio SOMA
2019 ◽  
Vol 13 (1) ◽  
pp. 73-81 ◽  
Author(s):  
J. Y. Zhou ◽  
E. Lowe ◽  
K. Cahill-Rowley ◽  
G. B. Mahtani ◽  
J. L. Young ◽  
...  

Purpose Spastic cerebral palsy (CP) is characterized by four neuromuscular deficits: weakness, short muscle-tendon unit, muscle spasticity and impaired selective motor control (SMC). We examined the influence of impaired SMC on gait in children with bilateral spastic CP. Delineating the influence of neuromuscular deficits on gait abnormalities can guide surgical and therapeutic interventions to reduce long-term debilitating effects of CP. Methods The relationship between impaired SMC and gait was assessed using multivariate linear regression analysis of Selective Control Assessment of the Lower Extremity (SCALE) in relation to stance phase knee flexion and temporal-spatial gait parameters calculated using 3D kinematics for 57 children with bilateral spastic CP, ages seven to 11 years. Results Mean SCALE values were 5.8 (0 to 10, sd 3.0) and 5.7 (0 to 10, sd 2.9) for right and left legs, respectively. Multivariate linear regression models, including right and left SCALE and height, significantly predicted right and left knee flexion at initial contact (R = 0.479, p = 0.003; R = 0.452, p = 0.007, respectively) and right and left knee flexion in midstance (R = 0.428, p = 0.013; R = 0.407, p = 0.022, respectively). The model significantly predicted right and left step length (R = 0.645, p = 0.000; R = 0.523, p = 0.001, respectively) and predicted gait velocity (R = 0.444, p = 0.008). The model including SCALE did not predict step width. Conclusion Results indicate impaired SMC predicts increased knee flexion at initial contact, and reduces step length and velocity. Understanding the influence of impaired SMC on gait can inform decisions regarding therapy and surgery, such as hamstring lengthening. Level of evidence Level II Retrospective Study


2005 ◽  
Vol 85 (8) ◽  
pp. 740-749 ◽  
Author(s):  
Terese L Chmielewski ◽  
Wendy J Hurd ◽  
Katherine S Rudolph ◽  
Michael J Axe ◽  
Lynn Snyder-Mackler

Abstract Background and Purpose. Dynamic knee stabilization strategies of people who successfully compensate for the absence of an anterior cruciate ligament (ACL) (“copers”) are different from those of people who do not compensate well for the injury (“noncopers”). Early after injury, certain patients (“potential copers”) can increase the likelihood of successfully compensating for the injury by participating in 10 sessions of perturbation training. The purpose of this study was to determine how perturbation training alters muscle co-contraction and knee kinematics in potential copers. Subjects. Seventeen individuals with acute, unilateral ACL rupture who were categorized as potential copers and 17 subjects without injuries who were matched by age, sex, and activity level were recruited for this study. Methods. Motion analysis and electromyographic data were collected as subjects walked across a stationary or moving platform (horizontal translation) before and after perturbation training. Results. Before training, potential copers had higher co-contraction indexes and lower peak knee flexion angles than subjects without injuries. After training, potential copers' movement patterns more closely resembled those of subjects without injuries (ie, they showed reduced co-contraction indexes and increased peak knee flexion angles during stance). Discussion and Conclusion. Perturbation training reduced quadriceps femoris-hamstring muscle and quadriceps femoris-gastrocnemius muscle co-contractions and normalized knee kinematics in individuals with ACL rupture who were classified as potential copers. Findings from this study provide evidence for a mechanism by which perturbation training acts as an effective intervention for promoting coordinated muscle activity in a select population of people with ACL rupture.


PLoS ONE ◽  
2019 ◽  
Vol 14 (7) ◽  
pp. e0220521 ◽  
Author(s):  
Guoqian Chen ◽  
Jiatao Wu ◽  
Guocai Chen ◽  
Yanyan Lu ◽  
Wei Ren ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document