Beyond Biology: The Importance of Gender in ACL Injuries and Physiotherapy in Victoria

At Pursuit Physiotherapy in Victoria, BC, we treat many patients recovering from anterior cruciate ligament (ACL) injuries. These injuries are common and challenging, particularly in sports. Research has shown that women are significantly more likely to suffer ACL injuries than men (1), and this gap has persisted for over 20 years. This has prompted us to look beyond biological differences and consider the role of gender.

Understanding the Gender Disparity in ACL Injuries

Traditionally, the focus on this disparity has been heavily on biological differences between sexes – things like hormones, anatomy, and physiology. This has certainly helped us understand some risk factors, mechanisms, and develop prevention programs. Exercise-based training, specifically, can reduce non-contact ACL injuries by as much as 67% when done consistently and in a structured, supervised manner(2). However, despite this knowledge and effort, the injury rate gap hasn't closed. This suggests that focusing solely on biology isn't enough. Our inspiration for our post today is a paper in the British Journal of Sports Medicine, which highlights a crucial missing piece in this conversation: gender (3).

The Entanglement of Sex and Gender

You might hear the terms "sex" and "gender" used interchangeably, but they are different and important to distinguish. Sex refers to biological characteristics (like hormones, genes, or anatomy), while gender refers to the identities, roles, and structures that are formed by society. Neither is strictly binary. The paper argues that sex and gender are actually 'entangled' – meaning biological and social factors influence each other in complex ways and cannot always be empirically discerned, but are theoretically plausible.

The authors propose thinking of gender as a "pervasive developmental environment". This means gender isn't just an individual identity; it's an external, environmental force that shapes experiences throughout an athlete's life. This environment is present from presport, to training and competition, through to treatment and rehabilitation.

They challenge the traditional idea of sorting risk factors into just "intrinsic" (inside the person) or "extrinsic" (outside the person). Many factors we think of as purely "intrinsic," like muscle strength, are heavily influenced by our environment and society. Here are some examples from the source of how gendered environments can influence the ACL injury cycle:

How Gendered Environments Influence ACL Injuries

1. The Presport Environment:

Long before formal sports, gendered social expectations begin shaping how girls and boys move and develop physical skills. Implicit gendered parenting, such as toy choices or allowing different levels of independent mobility, can require and develop different physical skill sets (4). Mothers have even been found to underestimate their daughters' crawling abilities while overestimating their sons' (5). These environmentally induced differences can lead to a motor control gender gap and possibly render the female-presenting body more susceptible to injury before even entering sport. The cultural phrase "throwing like a girl" is an example of how gender socialization manifests in bodily comportment and spatial mobility.

2. The Training Environment:

Building strength is key to ACL injury prevention. However, weight rooms can be highly gendered spaces where women often feel uncomfortable or that they don't belong. There are also strong gendered expectations that gaining muscle isn't desirable or socially acceptable for women (6). Since strength and conditioning (S&C) coaches are overwhelmingly men, this can further contribute to women feeling that weight rooms are not a place for them. These factors likely contribute to lower rates of resistance training among girls and women compared to boys and men. This lower participation is significant given the importance of strength training for effective ACL injury prevention programs. It's plausible that training environments are already different for girls and women in ways that disadvantage them. Even factors like the size of the ACL and femoral notch shape, traditionally seen as intrinsic anatomical risk factors, could be influenced by gendered processes through their impact on bone, joint, and muscle loading over time, highlighting the 'entanglement' of sex/gender.

3. The Competition Environment:

The way sports are structured is often gendered and binary, placing girls/women and boys/men in different playing situations. Examples include differences in allowed body-checking in ice hockey or game lengths in sports like Australian Rules football and tennis (7). Sport culture often values traditionally masculine traits like taking risks and playing through pain, which can lead to injury. Athletes, including women, might adopt these behaviours to fit in. This could lead to ignoring symptoms or playing when fatigued. Reduced cognitive function, potentially ignored due to pressure to play, has been linked to ACL risk (8). This demonstrates how gendered expectations and culture in competition could contribute to the injury disparity.

4. The Treatment Environment:

The influence of gender doesn't stop after an injury. Compared to men, after ACL reconstruction surgery, women often have greater knee laxity, lower patient-reported knee function, less chance of returning to sport, and a more frequent need for revision surgery (9). They are also more likely to need more surgery later, with a higher incidence of total knee arthroplasty within 20 years (10). There is evidence of potential institutional gender bias in recommending ACL reconstruction surgery more often to boys/men (11). If they do have surgery, women are more likely to require revision surgery. Men often return to sport more quickly than women. While this could be due to gendered expectations related to a masculine sport culture that values playing through pain, it could also relate to the training environments available during rehabilitation or the wider gendered context of women's lives – like taking on more family responsibilities (domestic and familial labour inequities) – which might impact their ability to fully commit to a lengthy rehab program.

Our Approach at Pursuit Physiotherapy

By viewing risk factors through a gendered environmental lens, factors previously seen as intrinsic and non-modifiable might be influenced by social and cultural expectations. This suggests that addressing injury risk can involve modifying the environment, not just the individual. Understanding and acting on these upstream social and contextual factors is vital for health.

What does this mean for us at Pursuit and for you, our patients? It means we need to look beyond just your body's biology. While we will absolutely address muscle strength, movement patterns, and your specific anatomy, we also need to consider the broader context of your life and sport experiences.

• Creating Supportive Training Environments: We strive to make training spaces comfortable and inclusive for everyone.

• Addressing Societal Expectations: We recognize how societal norms about women's bodies can impact engagement in strength training.

• Navigating Competitive Pressures: We are aware of how competition can influence decisions about playing through discomfort or adhering to safe return-to-sport protocols.

• Balancing Life Responsibilities: We understand that life outside of sport can impact rehabilitation adherence, and we work with you to find balanced solutions.

If you have questions about ACL injury prevention, rehabilitation, or how these factors relate to your experience, please reach out to your physiotherapist at Pursuit Physiotherapy.

For expert physiotherapy in Victoria, BC, and to learn more about treating sports injuries and ACL repair, contact Pursuit Physiotherapy today. We're here to support you on your journey to recovery.

References:

1.Lindenfeld TN , Schmitt DJ , Hendy MP , et al . Incidence of injury in indoor soccer. Am J Sports Med 1994;22:364–71.doi:10.1177/036354659402200312

2. Webster KE , Hewett TE . Meta-Analysis of meta-analyses of anterior cruciate ligament injury reduction training programs. J Orthop Res 2018;36:2696–708.doi:10.1002/jor.24043 pmid:http://www.ncbi.nlm.nih.gov/pubmed/29737024

3. Parsons JL, Coen SE, Bekker S. Anterior cruciate ligament injury: towards a gendered environmental approach. Br J Sports Med. 2021;55(17):984-990. doi:10.1136/bjsports-2020-103173

4. Ghekiere A , Deforche B , Carver A , et al . Insights into children's independent mobility for transportation cycling-Which socio-ecological factors matter? J Sci Med Sport 2017;20:267–72.doi:10.1016/j.jsams.2016.08.002

5. Mondschein ER , Adolph KE , Tamis-LeMonda CS . Gender bias in mothers' expectations about infant crawling. J Exp Child Psychol 2000;77:304–16.doi:10.1006/jecp.2000.2597 pmid:http://www.ncbi.nlm.nih.gov/pubmed/11063631

6.Coen SE , Rosenberg MW , Davidson J . “It’s gym, like g-y-m not J-i-m”: Exploring the role of place in the gendering of physical activity. Soc Sci Med 2018;196:29–36.doi:10.1016/j.socscimed.2017.10.036

7. de la Cretaz B . More girls are playing football. is that progress? The New York Times, 2018 February 2.

8.Swanik CB , Covassin T , Stearne DJ , et al . The relationship between neurocognitive function and noncontact anterior cruciate ligament injuries. Am J Sports Med 2007;35:943–8.doi:10.1177/0363546507299532

9. Tan SHS , Lau BPH , Khin LW , et al . The importance of patient sex in the outcomes of anterior cruciate ligament reconstructions: a systematic review and meta-analysis. Am J Sports Med 2016;44:242–54.doi:10.1177/0363546515573008 pmid:http://www.ncbi.nlm.nih.gov/pubmed/25802119

10. Abram SGF , Judge A , Khan T , et al . Rates of knee arthroplasty in anterior cruciate ligament reconstructed patients: a longitudinal cohort study of 111,212 procedures over 20 years. Acta Orthop 2019;90:568–74.doi:10.1080/17453674.2019.1639360

11.Collins JE , Katz JN , Donnell-Fink LA , et al . Cumulative incidence of ACL reconstruction after ACL injury in adults: role of age, sex, and race. Am J Sports Med 2013;41:544–9.doi:10.1177/0363546512472042 pmid:http://www.ncbi.nlm.nih.gov/pubmed/23302260