The Biomechanical Differences Between Men and Women in Sports
Snapping your fingers is a small, simple movement.
There are only three components on the surface. Your finger presses against your thumb, your finger comes off your thumb and your finger hits your palm. It’s a noise that anyone can create. It’s so easy a child can create a rhythm doing so without any training or effort. But underneath the surface there are 34 muscles working in tandem to make the movement possible.
18 of those muscles aren’t even in your hand, they’re in your forearm. Just to move your thumb alone, you need nine individual muscles and three major nerves.
Each hand has 27 bones, 29 joints, 48 nerves and 123 ligaments.
While our movements on the surface often seem simplistic, our bodies are incredibly complex. Our ability to move is made possible by the interdependence of muscles, ligaments and nerves. The joint at the base of your thumb is small but it has six different defined movements that all require the convergence of the body’s mechanics to occur.
Your body’s mechanics are any structures within the body that impact how the body moves.
Biomechanics is the study of the structure, function and motion of those mechanics. Men and women have different mechanics which is obviously hugely important to understand when it comes to physical activity and playing sport.
In the context of sports, biomechanists study the effects of various forces on athletic performance. The goal of biomechanists is in line with those working with athletes across different disciplines. They want to optimise the efficiency of each athlete’s movement for their sport and reduce injury risk moving forward.
Like most aspects of sports science, the research available is almost exclusively focused on elite male athletes with limited insight into the biomechanics of elite female athletes. There are important differences between male and female biomechanics.
These differences have implications for injury prevention strategies, training regimens and optimal equipment usage. Injury risk is a greater concern for female athletes than male athletes because of this lack of research.
Children are equal in terms of strength, aerobic power, weight and body fat until they reach puberty (Holschen, 2004). Puberty puts men and women on diverging paths. Anatomical differences between men and women give rise to biomechanical differences in both movement and injury propensity.
Women typically have a wider pelvis, femoral anteversion (inward twisting), knee valgus (knees collapsing in) and external tibial torsion (Feet turned outward). Women typically have smaller bones and smaller articular surfaces, while men proportionally have longer legs which results in increased potential force in certain maneuvers (Holschen, 2004).
These anatomical differences particularly impact lower limb biomechanics and neuromuscular activation during sports activities.
Women have a roughly 50% greater risk of common pathologies when they run. They are more likely to suffer from patella-femoral pain syndrome (PFPS), plantar fasciitis, and iliotibial band syndrome (ITBS) for example.
It’s not just a case of women being smaller so they’re more brittle. That’s a broad oversimplification that exists outside of the scientific community. It’s also not because their uteruses might fall out, as was once the argument against women running. There are nuanced differences between men’s and women’s bodies that have an impact on performance and injury risk.
For example, according to the Decker et al. study from 2003, during the stance phase of running women exhibit:
Greater adduction and internal rotation at the hip than men.
Greater abduction at the knee than men.
Greater eversion of the ankle than men.
Additionally, differences in gluteus medius and gluteus maximus activation during higher velocity running has been noted.
Ultimately, these factors combine so that there is an abnormal amount of force displaced to ligaments and supporting structures of the knee, hip and ankle which increases the risk of injury for women.
Jumping and Landing Mechanics
Most sports involve more movement than just running. Even if you’re a long-distance runner you’re going to have to change direction at some point. If you play a field sport, you’re more than likely going to make sharp cuts to turn and twist your body when reacting to the ball or your opponent.
In injury profiles, sports specific maneuvers have been related to gender differences. Jumping, landing and cutting movements notably contribute to injury incidence and injury risk in women compared to men.
Noncontact anterior cruciate ligament (ACL) injuries are common in sports that involve landing and cutting. Soccer and basketball players for example have to build their bodies to best be able to make sharp cuts and sudden turns. Upwards of 80% of ACL injuries occur without contact and female athletes are up to eight times more likely to sustain a non-contact ACL injury.
Women tend to land with decreased knee and hip flexion angles compared to men (Ferber et al., 2003; Pollard et al., 2004).
In addition to joint position, neuromuscular activation plays a role in female ACL injury mechanics. Women generate greater peak hip adduction, peak hip internal rotation, and peak knee abduction angles compared to their male counterparts. Women also have greater quadriceps activity and less hamstring activity than men (Malinzak et al., 2001).
Performance factors have been found to influence neuromuscular control and ACL injury risk. Notably muscular fatigue incurs a large neuromuscular deficit in female athletes compared to male athletes. Under muscular fatigue, women recorded an increase in anterior shear at the knee joint in comparison to men, further increasing risk of non-contact ACL injury (Kernozek et al., 2008).
Implications for Training and Coaching
Specifically designed training programmes that account for the anatomical variants between men and women can help to reduce the associated risk for female athletes. Neuromuscular training programmes that purposely target the known differences between men and women have been beneficial in reducing incidence of ACL injury.
Training that includes dynamic, sensory stimulus to enhance subconscious control of the knee joint movement is an important consideration for coaches and support staff working with women. The inclusion of neuromuscular stimulation training improves muscle activation patterns, speed of response to joint movement (proprioception), increases stability and maladaptive decreases joint forces thus reducing injury risk (Mandelbaum et al., 2005).
There is strong research evidence to support the use of this type of training in female soccer players. A large-scale, multi-season research project examined the effect of training intervention to reduce ACL injury risk in 2005.
The study (Mandelbaum et al., 2005) looked a the difference in ACL injury rate over two seasons for a group of players with and without nueromuscular training for knee landing mechanics. 52 teams were included and the teams were followed over 2 seasons.
With the neuromuscular training, significant reductions in ACL injury incidence were recorded over two seasons (88% reduction and 74% reduction). The intervention consisted of education, stretching, strengthening, plyometrics and sports-specific agility drills designed to replace the traditional warm-up.
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