The knee abduction moment in a weight-bearing limb is an important risk factor of conditions such... more The knee abduction moment in a weight-bearing limb is an important risk factor of conditions such as patellofemoral pain and knee osteoarthritis. Excessive pelvic drop in single-leg stance can increase the knee abduction moment. The gluteus medius muscle is crucial to prevent pelvic drop and must be activated in anticipation of the transition from double-leg to single-leg stance. To examine the relationship of anticipatory activity of the gluteus medius to pelvic drop and knee abduction moment. Observational, cross-sectional correlational study. Research laboratory. Twenty female adults (mean age 22.6 years, standard deviation 2.5) were recruited and fully participated. Participant selection was limited to healthy women who did not have a history of knee and ankle ligament injuries, any indication of knee, hip, and/or low back pain, and/or knowledge of the proper squat technique. Participants performed 16 single-leg mini squats on their nondominant leg. The onset and magnitude of anticipatory gluteus medius activity were measured in relation to toe-off of the dominant leg during the transition from double-leg to single-leg stance. Preplanned correlations between anticipatory gluteus medius onset and its activation magnitude, pelvic obliquity, and knee abduction moment were examined. The magnitude of anticipatory gluteus medius activity was significantly correlated with the knee abduction moment (rs (18) = -0.303, P < .001) and pelvic obliquity (rs (18) = 0.361, P < .001), whereas gluteus medius onset was not significantly correlated with either knee abduction moment or pelvic obliquity. The amount of gluteus medius activity is more important for controlling knee and pelvic stability in the frontal plane than the onset of activation.
Emergence of proprioceptive training in industrial training facilities seems to reflect current e... more Emergence of proprioceptive training in industrial training facilities seems to reflect current efforts of emphasizing neuromuscular function and postural control in general training programs. While it is encouraged to continue such efforts, correction of mythical beliefs is necessary for more suitable application. Clinicians for the recovery of the sensorimotor function originally suggested the idea of proprioceptive training. Adopting this clinically originated concept to general training created two main misconceptions. One is the premature assumption that proprioception can be improved with physical training. The other is the belief that proprioception is a key factor for the improvement of balance in every occasions. However, there is not sufficient neurophysiological evidence supporting the feasibility of the improvement of the proprioception through physical training. Moreover, proprioception can be effectively used only during the slow or moderately fast closed-loop control of movement. Therefore, overemphasis on proprioception may ignore the role of the central nervous system (CNS) in carrying out motor abilities and skills. A training program should be able to facilitate the CNS adaptation that is a key factor for the development of motor abilities and improvement of skill performance. In order to create an ideal learning environment for the CNS, an exercise program should distinctively train different motor skills with adequately changing task goals and sensory environment. Also, training should help the CNS to overcome its limited attentional capacity by adequately imposing multiple task demands.
Key words: Balance, motor control, proprioception, central nervous system, exercise program, application of therapeutic exercise.
Previous studies have proposed that thigh muscle imbalance is a critical risk factor for the athl... more Previous studies have proposed that thigh muscle imbalance is a critical risk factor for the athletic non-contact knee injuries. However, there is a little consensus among prospective studies with regard to the correlation between isokinetic hamstring to quadriceps strength ratio (HQR) and the non-contact knee injury rates. Most of athletic movements at risk are closed kinetic chain movements, and compensatory effect among ankle, knee, and hip joints during the closed kinetic chain movement was observed in the previous literatures. Therefore, it is assumed that hamstrings and quadriceps (H:Q) imbalance can cause non-contact lower extremity injuries without necessarily causing knee injuries. The purpose of this study was to prospectively investigate the relationship between H:Q strength imbalance and overall non-contact lower extremity injuries. A prospective cohort study was conducted on NCAA division III basketball and soccer players during one season. A total of eighty two NCAA Division III athletes (41 female [19.56 ± 1.34 yrs, 68.2 ± 10.84 kg, 166.3 ± 6.78 cm] and 40 male [19.97 ± 1.43 yrs, 75.45 ± 8.23 kg, 173.21 ± 7.65 cm]) volunteered to participate in this study which tested Q and H strength at 60°/s. A trend (p< 0.05) indicating that lower than 60% of HQR was associated with non-contact leg injuries was apparent. This suggests that the H:Q imbalance may be of significance in athletic non-contact leg injuries.
The knee abduction moment in a weight-bearing limb is an important risk factor of conditions such... more The knee abduction moment in a weight-bearing limb is an important risk factor of conditions such as patellofemoral pain and knee osteoarthritis. Excessive pelvic drop in single-leg stance can increase the knee abduction moment. The gluteus medius muscle is crucial to prevent pelvic drop and must be activated in anticipation of the transition from double-leg to single-leg stance. To examine the relationship of anticipatory activity of the gluteus medius to pelvic drop and knee abduction moment. Observational, cross-sectional correlational study. Research laboratory. Twenty female adults (mean age 22.6 years, standard deviation 2.5) were recruited and fully participated. Participant selection was limited to healthy women who did not have a history of knee and ankle ligament injuries, any indication of knee, hip, and/or low back pain, and/or knowledge of the proper squat technique. Participants performed 16 single-leg mini squats on their nondominant leg. The onset and magnitude of anticipatory gluteus medius activity were measured in relation to toe-off of the dominant leg during the transition from double-leg to single-leg stance. Preplanned correlations between anticipatory gluteus medius onset and its activation magnitude, pelvic obliquity, and knee abduction moment were examined. The magnitude of anticipatory gluteus medius activity was significantly correlated with the knee abduction moment (rs (18) = -0.303, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001) and pelvic obliquity (rs (18) = 0.361, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001), whereas gluteus medius onset was not significantly correlated with either knee abduction moment or pelvic obliquity. The amount of gluteus medius activity is more important for controlling knee and pelvic stability in the frontal plane than the onset of activation.
Emergence of proprioceptive training in industrial training facilities seems to reflect current e... more Emergence of proprioceptive training in industrial training facilities seems to reflect current efforts of emphasizing neuromuscular function and postural control in general training programs. While it is encouraged to continue such efforts, correction of mythical beliefs is necessary for more suitable application. Clinicians for the recovery of the sensorimotor function originally suggested the idea of proprioceptive training. Adopting this clinically originated concept to general training created two main misconceptions. One is the premature assumption that proprioception can be improved with physical training. The other is the belief that proprioception is a key factor for the improvement of balance in every occasions. However, there is not sufficient neurophysiological evidence supporting the feasibility of the improvement of the proprioception through physical training. Moreover, proprioception can be effectively used only during the slow or moderately fast closed-loop control of movement. Therefore, overemphasis on proprioception may ignore the role of the central nervous system (CNS) in carrying out motor abilities and skills. A training program should be able to facilitate the CNS adaptation that is a key factor for the development of motor abilities and improvement of skill performance. In order to create an ideal learning environment for the CNS, an exercise program should distinctively train different motor skills with adequately changing task goals and sensory environment. Also, training should help the CNS to overcome its limited attentional capacity by adequately imposing multiple task demands.
Key words: Balance, motor control, proprioception, central nervous system, exercise program, application of therapeutic exercise.
Previous studies have proposed that thigh muscle imbalance is a critical risk factor for the athl... more Previous studies have proposed that thigh muscle imbalance is a critical risk factor for the athletic non-contact knee injuries. However, there is a little consensus among prospective studies with regard to the correlation between isokinetic hamstring to quadriceps strength ratio (HQR) and the non-contact knee injury rates. Most of athletic movements at risk are closed kinetic chain movements, and compensatory effect among ankle, knee, and hip joints during the closed kinetic chain movement was observed in the previous literatures. Therefore, it is assumed that hamstrings and quadriceps (H:Q) imbalance can cause non-contact lower extremity injuries without necessarily causing knee injuries. The purpose of this study was to prospectively investigate the relationship between H:Q strength imbalance and overall non-contact lower extremity injuries. A prospective cohort study was conducted on NCAA division III basketball and soccer players during one season. A total of eighty two NCAA Division III athletes (41 female [19.56 ± 1.34 yrs, 68.2 ± 10.84 kg, 166.3 ± 6.78 cm] and 40 male [19.97 ± 1.43 yrs, 75.45 ± 8.23 kg, 173.21 ± 7.65 cm]) volunteered to participate in this study which tested Q and H strength at 60°/s. A trend (p< 0.05) indicating that lower than 60% of HQR was associated with non-contact leg injuries was apparent. This suggests that the H:Q imbalance may be of significance in athletic non-contact leg injuries.
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Papers by Daehan Kim
Key words: Balance, motor control, proprioception, central nervous system, exercise program, application of therapeutic exercise.
Read more: http://www.readperiodicals.com/201104/2306736741.html#ixzz1ypYBxIA0
Keywords
Kinetic integration, isokinetic strength, neuromuscular, co-contraction, plyometrics, prophylactic
Key words: Balance, motor control, proprioception, central nervous system, exercise program, application of therapeutic exercise.
Read more: http://www.readperiodicals.com/201104/2306736741.html#ixzz1ypYBxIA0
Keywords
Kinetic integration, isokinetic strength, neuromuscular, co-contraction, plyometrics, prophylactic