Relationships between knee valgus, hip-muscle strength, and hip-muscle recruitment during a single-limb step-down.

CONTEXT Reduced strength and activation of hip muscles might correlate with increased weight-bearing knee valgus. OBJECTIVE To describe relationships among frontal-plane hip and knee angles, hip-muscle strength, and electromyographic (EMG) recruitment in women during a step-down. DESIGN Exploratory study. SETTING Laboratory. PARTICIPANTS 20 healthy women 20 to 30 years of age. INTERVENTIONS Frontal-plane hip and knee angles were measured. Gluteus maximus and medius recruitment were examined with surface EMG. Hip-abduction and -external-rotation strength were quantified with handheld dynamometry. MAIN OUTCOME MEASUREMENTS The authors analyzed correlation coefficients between knee and hip angles, gluteus maximus and medius EMG, and hip-abduction and -external-rotation strength. RESULTS Hip-adduction angles (r = .755, P = .001), gluteus maximus EMG (r = -.451, P = .026), and hip-abduction strength (r = .455, P = .022) correlated with frontal-plane projections of knee valgus. CONCLUSIONS Gluteus maximus recruitment might have greater association with reduced knee valgus in women than does external-rotation strength during step-down tasks. Gluteus medius strength might be associated with increased knee valgus.

[1]  K. Markolf,et al.  Combined knee loading states that generate high anterior cruciate ligament forces , 1995, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[2]  Mary Lloyd Ireland,et al.  Core strength and lower extremity alignment during single leg squats. , 2006, Medicine and science in sports and exercise.

[3]  Freddie H Fu,et al.  Gender Differences in Strength and Lower Extremity Kinematics During Landing , 2002, Clinical orthopaedics and related research.

[4]  Kevin R Ford,et al.  Valgus knee motion during landing in high school female and male basketball players. , 2003, Medicine and science in sports and exercise.

[5]  J. Cram,et al.  Introduction to Surface Electromyography , 1998 .

[6]  Jan Quintelier,et al.  Patellofemoral contact pressures. , 2008, Acta of bioengineering and biomechanics.

[7]  F. P. Kendall,et al.  Muscles: Testing and Function, with Posture and Pain , 1993 .

[8]  Bing Yu,et al.  Kinematics and Electromyography of Landing Preparation in Vertical Stop-Jump , 2007, The American journal of sports medicine.

[9]  A J van den Bogert,et al.  Evaluation of a two dimensional analysis method as a screening and evaluation tool for anterior cruciate ligament injury , 2005, British Journal of Sports Medicine.

[10]  Timothy E Hewett,et al.  Estimating 3D joint kinematics from video sequences of running and cutting maneuvers--assessing the accuracy of simple visual inspection. , 2007, Gait & posture.

[11]  J. Fleiss,et al.  Intraclass correlations: uses in assessing rater reliability. , 1979, Psychological bulletin.

[12]  S. Delp,et al.  Variation of rotation moment arms with hip flexion. , 1999, Journal of biomechanics.

[13]  W C Hayes,et al.  Patellofemoral contact pressures. The influence of q-angle and tendofemoral contact. , 1984, The Journal of bone and joint surgery. American volume.

[14]  C. Powers.  The influence of altered lower-extremity kinematics on patellofemoral joint dysfunction: a theoretical perspective. , 2003, The Journal of orthopaedic and sports physical therapy.

[15]  J. Nicholas,et al.  A study of thigh muscle weakness in different pathological states of the lower extremity , 1976, The American journal of sports medicine.

[16]  W E Garrett,et al.  A comparison of knee joint motion patterns between men and women in selected athletic tasks. , 2001, Clinical biomechanics.

[17]  R. H. Deusinger,et al.  Gender Differences in Surface Rolling and Gliding Kinematics of the Knee , 2003, Clinical orthopaedics and related research.

[18]  Timothy L. Uhl,et al.  Differences in Kinematics and Electromyographic Activity between Men and Women during the Single-Legged Squat * , 2003, The American journal of sports medicine.

[19]  R. Ferber,et al.  Gender differences in lower extremity mechanics during running. , 2003, Clinical biomechanics.

[20]  H. Hislop,et al.  Daniel's and Worthingham's muscle testing : techniques of manual examination , 1995 .

[21]  Kevin R Ford,et al.  Gender differences in the kinematics of unanticipated cutting in young athletes. , 2005, Medicine and science in sports and exercise.

[22]  T. Hewett,et al.  Biomechanical Measures of Neuromuscular Control and Valgus Loading of the Knee Predict Anterior Cruciate Ligament Injury Risk in Female Athletes: A Prospective Study , 2005, The American journal of sports medicine.

[23]  E. Arendt,et al.  Anterior knee pain in females. , 2000, Clinical orthopaedics and related research.

[24]  S. Schulthies,et al.  Does the Q angle reflect the force on the patella in the frontal plane? , 1995, Physical therapy.

[25]  T. Hewett,et al.  Gender comparison of hip muscle activity during single-leg landing. , 2005, The Journal of orthopaedic and sports physical therapy.

[26]  J. Fulkerson,et al.  Diagnosis and Treatment of Patients with Patellofemoral Pain , 2002, The American journal of sports medicine.

[27]  I. Davis,et al.  Hip strength in females with and without patellofemoral pain. , 2003, The Journal of orthopaedic and sports physical therapy.

[28]  S. Sahrmann,et al.  Hip Abductor Weakness in Distance Runners with Iliotibial Band Syndrome , 2000, Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine.

[29]  M. J. Myers,et al.  Hip Muscle Weakness and Overuse Injuries in Recreational Runners , 2005, Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine.