A Comparison of Range of Motion of Joints and Isometric Strength of Lower Extremity Muscles in Female Athletes with and without Dynamic Knee Valgus

Document Type : Research Paper


1 PhD Student of Corrective Exercises, Faculty of Physical Education and Sport Sciences, University of Guilan, Rasht, Iran

2 Professor, Faculty of Physical Education and Sport Sciences, University of Guilan, Rasht, Iran

3 Associate Professor, Faculty of Physical Education and Sport Sciences, University of Guilan, Rasht, Iran


The aim of this study was to compare isometric strength and range of motion (ROM) of lower extremity in female athletes with and without dynamic knee valgus. 48 healthy female athletes (age range 15-18 years) in two groups: those with dynamic knee valgus during squat movement that was corrected by a heel lift (n=24) and those with no dynamic knee valgus (n=24 as the control group) with no injury in the past participated in this study. Maximum isometric strength was measured in kilograms using a hand-held dynamometer and active ROM was measured in degrees with a standard plastic goniometer. Independent t test and MANOVA were used to analyze data (P≤0.05). The results showed that the group with dynamic knee valgus had significantly lower mean ankle dorsiflexion ROM (with right knee) (F1.46=5.503, P=0.023) and isometric strength of ankle plantar flexion (F1.46=4.187, P=0.046) than the control group. No other significant differences were observed between the groups. The subjects with dynamic knee valgus exhibited tight and weak lateral and medial gastrocnemius muscles. This result indicated that decreased ankle dorsiflexion ROM as a factor affecting the alteration of movement pattern of lower extremity and consequently a risk factor for knee injuries must receive the attention of clinicians and trainers.


.               Bell, D.R., et al., Two-and 3-dimensional knee valgus are reduced after an exercise intervention in young adults with demonstrable valgus during squatting. Journal of athletic training, 2013. 48(4): p. 442-449.
2.            Bell, D.R., D.A. Padua, and M.A. Clark, Muscle strength and flexibility characteristics of people displaying excessive medial knee displacement. Archives of physical medicine and rehabilitation, 2008. 89(7): p. 1323-1328.
3.            Bennell, K.L., et al., The effects of hip muscle strengthening on knee load, pain, and function in people with knee osteoarthritis: a protocol for a randomised, single-blind controlled trial. BMC musculoskeletal disorders, 2007. 8(1): p. 121.
4.            Boling, M., et al., Gender differences in the incidence and prevalence of patellofemoral pain syndrome. Scandinavian journal of medicine & science in sports, 2010. 20(5): p. 725-730.
5.            Claiborne, T.L., et al., Relationship between hip and knee strength and knee valgus during a single leg squat. Journal of applied biomechanics, 200606. 22(1): p. 41-50.
6.            Cook, G., L. Burton, and B. Hoogenboom, Pre-participation screening: the use of fundamental movements as an assessment of function–part 1. North American journal of sports physical therapy: NAJSPT, 2006. 1(2): p. 62.
7.            Cronin, B., et al., Greater Hip Extension but Not Hip Abduction Explosive Strength Is Associated With Lesser Hip Adduction and Knee Valgus Motion During a Single-Leg Jump-Cut. Orthopaedic journal of sports medicine, 2016. 4(4): p. 2325967116639578.
8.            Dill, K.E., et al., Altered knee and ankle kinematics during squatting in those with limited weight-bearing–lunge ankle-dorsiflexion range of motion. Journal of athletic training, 2014. 49(6): p. 723-732.
9.            Ford, K.R., et al., An evidence-based review of hip-focused neuromuscular exercise interventions to address dynamic lower extremity valgus. Open access journal of sports medicine, 2015. 6: p. 291.
10.          Goto, S., The effects of an integrated exercise program on lower extremity biomechanics in females with medial knee displacement. 2015: THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL.
11.          Heinert, B.L., et al., Hip abductor weakness and lower extremity kinematics during running. Journal of sport rehabilitation, 2008. 17(3): p. 243-256.
12.          Hewett, T.E., G.D. Myer, and K.R. Ford, Decrease in neuromuscular control about the knee with maturation in female athletes. J Bone Joint Surg Am, 2004. 86(8): p. 1601-1608.
13.          Hollman, J.H., et al., Relationships between knee valgus, hip-muscle strength, and hip-muscle recruitment during a single-limb step-down. Journal of sport rehabilitation, 2009. 18(1): p. 104-117.
14.          Hollman, J.H., et al., Modulation of frontal-plane knee kinematics by hip-extensor strength and gluteus maximus recruitment during a jump-landing task in healthy women. Journal of sport rehabilitation, 2013. 22(3): p. 184-190.
15.          Homan, K.J., et al., The influence of hip strength on gluteal activity and lower extremity kinematics. Journal of Electromyography and Kinesiology, 2013. 23(2): p. 411-415.
16.          Jacobs, C.A., et al., Hip abductor function and lower extremity landing kinematics: sex differences. Journal of athletic training, 2007. 42(1): p. 76.
17.          Joseph, A.M., et al., A multisport epidemiologic comparison of anterior cruciate ligament injuries in high school athletics. Journal of athletic training, 2013. 48(6): p. 810-817.
18.          Kagaya, Y., Y. Fujii, and H. Nishizono, Association between hip abductor function, rear-foot dynamic alignment, and dynamic knee valgus during single-leg squats and drop landings. Journal of Sport and Health Science, 2015. 4(2): p. 182-187.
19.          Malloy, P., et al., The association of dorsiflexion flexibility on knee kinematics and kinetics during a drop vertical jump in healthy female athletes. Knee Surgery, Sports Traumatology, Arthroscopy, 2015. 23(12): p. 3550-3555.
20.          Munro, A., L. Herrington, and M. Carolan, Reliability of 2-dimensional video assessment of frontal-plane dynamic knee valgus during common athletic screening tasks. Journal of sport rehabilitation, 2012. 21(1): p. 7-11.
21.          Norkin, C.C. and D.J. White, Measurement of joint motion: a guide to goniometry. 2016: FA Davis.
22.          Padua, D.A., D.R. Bell, and M.A. Clark, Neuromuscular characteristics of individuals displaying excessive medial knee displacement. Journal of athletic training, 2012. 47(5): p. 525-536.
23.          Patrek, M.F., et al., Hip-abductor fatigue and single-leg landing mechanics in women athletes. Journal of athletic training, 2011. 46(1): p. 31-42.
24.          Piva, S.R., E.A. Goodnite, and J.D. Childs, Strength around the hip and flexibility of soft tissues in individuals with and without patellofemoral pain syndrome. Journal of orthopaedic & sports physical therapy, 2005. 35(12): p. 793-801.
25.          Rabin, A. and Z. Kozol, Measures of range of motion and strength among healthy women with differing quality of lower extremity movement during the lateral step-down test. Journal of orthopaedic & sports physical therapy, 2010. 40(12): p. 792-800.
26.          Rabin, A., Z. Kozol, and A.S. Finestone, Limited ankle dorsiflexion increases the risk for mid-portion Achilles tendinopathy in infantry recruits: a prospective cohort study. Journal of foot and ankle research, 2014. 7(1): p. 48.
27.          Schmitz, R.J., S.J. Shultz, and A.-D. Nguyen, Dynamic valgus alignment and functional strength in males and females during maturation. Journal of athletic training, 2009. 44(1): p. 26-32.
28.          Sigward, S.M., S. Ota, and C.M. Powers, Predictors of frontal plane knee excursion during a drop land in young female soccer players. Journal of orthopaedic & sports physical therapy, 2008. 38(11): p. 661-667.
29.          Stickler, L., M. Goehring, and B. Kinne, The impact of hip strengthening and/or neuromuscular control on frontal plane knee kinematics and kinetics in females: a systematic review. Physical Therapy Reviews, 2016. 21(1): p. 10-16.
30.          Thijs, Y., et al., Relationship between hip strength and frontal plane posture of the knee during a forward lunge. British journal of sports medicine, 2007. 41(11): p. 723-727.
31.          Willy, R.W. and I.S. Davis, The effect of a hip-strengthening program on mechanics during running and during a single-leg squat. journal of orthopaedic & sports physical therapy, 2011. 41(9): p. 625-632.