Does gender influence neuromotor control of the knee and hip?
Introduction
Patellofemoral pain (PFP) is a common condition, affecting individuals from both the sporting and general populations (DeHaven et al., 1979, Levine, 1979, Sandow and Goodfellow, 1985, DeHaven and Lintner, 1986, Milgrom et al., 1996, Baquie and Brukner, 1997). PFP is commonly hypothesised to occur due to lateral patellar tracking (Wise et al., 1984). Of those affected, the condition occurs more frequently in females (DeHaven and Lintner, 1986, Taunton et al., 2002). While the reasons for this are unclear (Biedert and Sanchis-Alfonso, 2002) anatomical, hormonal and neuromuscular factors have been proposed (Hewett, 2000).
Anatomical factors which may lead to lateral patellar tracking in females include a larger Q angle (Zelisko et al., 1982, Gray et al., 1985), a higher pelvis–femoral-length ratio (Horton and Hall, 1989) and greater ligamentous laxity (Decoster et al., 1999, Karageanes et al., 2000). Hormonal factors relate the effects of female hormones such as estrogen, progesterone and relaxin on the female neuromuscular and musculoskeletal systems (Chandy and Grana, 1985, Posthuma et al., 1987, Lebrun, 1994, Houston and Wojtys, 1996, Sarwar et al., 1996). However whilst these factors may influence the development of PFP in females, research has not demonstrated that any of the aforementioned factors do play a role in the development of PFP in females. Furthermore, interventions to reduce the incidence of PFP are unlikely to influence anatomic and hormonal factors. Thus the importance of neuromuscular mechanisms over which clinicians may have some influence cannot be over-stated.
Neuromuscular mechanisms, which are amenable to change with intervention, may be of particular importance. Females with PFP have been found to have reduced hip muscle strength (Ireland et al., 2003). Furthermore, females have been found to land in more knee valgus during a single leg drop (Russell et al., 2006) and a double leg drop jump (Ford et al., 2003, Hewett et al., 2005). While there is some evidence that the neuromuscular control of the hip may differ between the genders, it is not known whether the timing of the gluteus medius muscles differs between men and women. Furthermore, since genu valgus and hip internal rotation may increase the loads on the lateral patellofemoral joint, it is possible that the neuromuscular factors at the hip may be associated with alterations in the neuromotor control of the vasti in women, which may predispose to PFP.
Studies have provided evidence of an imbalance in the activation of the timing of vastus medialis oblique (VMO) and vastus lateralis (VL) in people with PFP (Witvrouw et al., 1996, Cowan et al., 2001, Cowan et al., 2002a, Cowan et al., 2002b), and that an altered reflex response time of VMO is a risk factor for the development of PFP (Witvrouw et al., 2000). Thus it is plausible that altered activation of the vasti in females may predispose them to PFP, however this question has not been addressed in the literature. A number of electromyographical studies have demonstrated that neuromuscular control in women differs from that in men (Rozzi et al., 1999, White et al., 2003, Sell et al., 2004, Myer et al., 2005). Only one study has specifically aimed to investigate vasti control between genders, Myer et al. (2005) found that females demonstrated a decreased ratio of VMO to VL recruitment during a dynamic task. However this study did not investigate the timing of vasti activation.
Thus the aim of this study was twofold. Firstly, to determine if the timing of EMG activation of the knee and hip differs between genders during a stepping task. Secondly, to investigate whether clinical measures of hip rotation ROM and strength (known to be less in women) are associated with EMG measures of motor control of the knee and hip. It is hypothesised that females will present with a delayed activation of their VMO and/or gluteus medius and that individuals with increased hip internal rotation and decreased hip strength will present with a greater delay in the activation of their knee and hip muscles
Section snippets
Participants
Twenty-nine (16 female and 13 male) asymptomatic participants were recruited from the staff and student body of the University of Melbourne. Participants were examined by an experienced musculoskeletal physiotherapist and were excluded if they had any history of lower limb pathology or other disorder that might interfere with the kinetics or kinematics of knee and hip motion.
The project was approved by the University of Melbourne Human Research Ethics Committee. All participants provided
Participant Characteristics
Males were 25.7(5.3) yr old, 1.77(0.07) m tall and weighed 74(9) kg. Females were 22.5(5.0) yr, 1.64(0.08) m tall and weighed 60(10) kg. Participants were evenly matched for age (p = 0.106), however males were significantly taller (p = 0.000) and heavier (p = 0.001).
Does motor control of the thigh and leg differ between genders during stair stepping?
When male and female participants completed the visual choice reaction-time stepping task there were no significant differences between groups for any of the EMG variables collected (onset timing VMO, VL, AGM, PGM and time to peak muscle
Does motor control of the thigh and leg differ between genders during a stair stepping task?
The results demonstrate that there were no differences in the onset of EMG or peak activity of the thigh and leg muscles between genders in the stair stepping task. Due to differences in strength at the hip it had been postulated that females may present with differing patterns of motor control. Indeed whilst our results confirmed that females were indeed weaker than males, we found no differences in the motor control of the quads or gluteals when comparing males and females in this task. This
Conclusion
There were no differences in the timing or peak of EMG activation of the gluteus medius or vasti muscles between genders during a stepping task. However there were significant associations between EMG measures of motor control of the vasti and the hip strength in both females and males, suggestive of a link between hip muscle control and vasti neuromotor control.
Dr Sallie M. Cowan completed a PhD in 2002 investigating motor control of the patellofemoral joint. In 2003 she was awarded a Post Doctoral Training Research Fellowship (National Health and Medical Research Council of Australia). Her research focuses on investigating the relationship between motor control at the hip and the vasti. She is an experienced musculoskeletal physiotherapist who continues clinical practice at a multidisciplinary sports and spinal practice.
References (44)
- et al.
Sources of anterior knee pain
Clin Sports Med
(2002) Reference values for extremity muscle strength obtained by hand-held dynamometry from adults aged 20 to 79 years
Arch Phys Med Rehab
(1997)- et al.
Delayed onset of electromyographic activity of vastus lateralis compared to vastus medialis obliquus in subjects with patellofemoral pain syndrome
Arch Phys Med Rehab
(2001) - et al.
Altered vasti recruitment when people with patellofemoral pain syndrome complete a postural task
Arch Phys Med Rehab
(2002) The effect of the phase of the menstrual cyle and the birth control pill in athletic performance
Clin Sports Med
(1994)- et al.
The effects of gender on quadriceps muscle activation strategies during a manoeuvre that mimics a high ACL injury risk position
J Electromyogr Kinesiol
(2005) - et al.
Detecting changes in functional ability in women with premenstrual syndrome
Am J Obstet Gynecol
(1987) - et al.
Injuries presenting to an Australian sports medicine centre – a 12 month study
Clin J Sports Med
(1997) - et al.
Quantitative measurements of hip strengthin different age groups
Clin Orthop
(1989) - et al.
Secondary school athletic injury in boys and girls: a three year comparison
Phys Sports Med
(1985)
Physical therapy alters the recruitment of the vasti in patellofemoral pain syndrome
Med Sci Sports Exer
Generalised joint hypermobility and its relationship to injury patterns among NCAA lacrosse players
J Athl Training
Athletic injuries: comparison by age, sport and gender
Am J Sports Med
Chondromalacia in athletes
Am J Sports Med
Valgus knee motion during landing in high school female and male basketball players
Med Sci Sports Exer
Diagnosis and treatment of patients with patellofemoral pain
Am J Sports Med
A survey of injuries to the anterior cruciate ligament of the knee in female basketball players
Int J Sports Med
Neuromuscular and hormonal factors associated iwth knee injuries in female athletes
Sports Med
Biomechanical measures of neuromuscular control and valgus loading of the knee predict anterior cruciate ligament injury risk in female athletes: a prospective study
Am J Sports Med
Validation of a technique for fine-wore electrode placement into posterior gluteus medius using real-time ultrasound guidance
Electromyogr Clin Neurophysiol
Quadriceps femoris muscle angle: normal values and relationship with gender and selected skeletal measures
Phys Ther
Neuromuscular performance characteristics in elite female athletes
Am J Sports Med
Cited by (0)
Dr Sallie M. Cowan completed a PhD in 2002 investigating motor control of the patellofemoral joint. In 2003 she was awarded a Post Doctoral Training Research Fellowship (National Health and Medical Research Council of Australia). Her research focuses on investigating the relationship between motor control at the hip and the vasti. She is an experienced musculoskeletal physiotherapist who continues clinical practice at a multidisciplinary sports and spinal practice.
Dr Kay M. Crossley is a Principal Research Fellow in the Department of Mechanical and manufacturing Engineering at The University of Melbourne. Her research focuses on musculoskeletal disorders, especially knee pain; evaluating contributing factors and mechanisms underpinning interventions and their efficacy. In her current position, she is working with a research team evaluating the role of knee joint stress in knee conditions (especially osteoarthritis). Kay continues to practice in a multidisciplinary centre, in the field of sports physiotherapy.