Study Finds Surprising Differences in Knee Injuries Between Men and Women

• The research rationale — Past studies primarily focused on sports injuries often concluded that young women athletes were at higher risk for ACL tears. Now, the team wanted to see if those patterns held in the general population. Dr. Jenifer Pitman, the study co-author and assistant professor of radiology at Johns Hopkins Medical Institute, said:⁷

“In recent years, we’ve grown more interested in the differences in knee injuries between men and women. The majority of past research has focused on men, but as we expand our focus to include women, the more we see that they have different risk profiles and are prone to different injuries.”

• Many people, one complaint — Researchers analyzed 13,549 consecutive knee MRI exams performed between 2019 and 2024 at four outpatient facilities affiliated with Johns Hopkins Hospital. All patients reported knee pain as their chief complaint.⁸

• What the researchers looked at — The team extracted data on the presence or absence of tears in the following key structures:⁹

• New data challenges old assumptions about ACL injuries — Researchers found that ACL tears were more common in men, especially between ages 20 and 40. Patterns differed for meniscal and MCL, which were more common in younger men but became more prevalent in women over 40, pointing to degenerative changes with age.

Overall, men had more knee injuries than women across all age groups.¹⁰ These findings contradict older sports-focused studies that suggested women were at higher risk for ACL tears.

“Prior studies focused on sports-related injuries have shown that young women athletes have increased rates of and a greater risk for ACL tears. However, our results show a significantly higher prevalence of ACL injuries in male patients across all age groups,” lead author Dr. Ali Ghasemi said.

• Key takeaway — Pitman advises both men and women to take precautions to reduce high-impact knee injuries during sports and physical activity. Women over 40, in particular, need to pay attention to joint health and incorporate dedicated strength training to protect their knees as they age. “If you’re having knee pain, don’t just brush it off or attribute it to old age,” she said.¹¹

• Why this matters for clinicians — Recognizing these patterns can help radiologists and clinicians tailor imaging protocols, risk assessments, and early intervention strategies, and guide personalized care to help prevent long-term joint damage.¹²

• Men and women tear the ACL the same way in noncontact injuries — A 2018 study published in The American Journal of Sports Medicine¹³ examined MRI scans taken within a month of injury and used bone bruises — marks left on the thighbone and shinbone during impact to reconstruct the knee’s position at the exact time of the tear.

In 30 patients, they found the same position that caused injury in both genders — landing on a too‑straight (hyperextended) knee. Biomedical engineer and lead study author Louis DeFrate, Ph.D., explained:¹⁴

“In order to develop improved treatment strategies and prevention, we need a clear understanding of what motions are most dangerous for athletes. This work provides new evidence that landing on an extended knee may be a dangerous position for ACL tears in both males and females.”

This challenges the common idea that women primarily tear the ACL because the knee collapses inward first. The data suggests the pivotal moment is near hyperextension; the inward buckle may come afterward. That shifts prevention toward teaching deeper landings, trunk control, and earlier deceleration in both men and women.

• How ACL risk estimates are calculated matters — A 2023 analysis published in the British Journal of Sports Medicine, summarized by the University of Bath, examined how commonly cited claims that women are two to 10 times more likely to tear an ACL are derived and interpreted.

Study author Sheree Bekker, Ph.D., noted that prevailing methods embed bias into risk calculations and frame ACL injuries in ways that shape participation decisions more than they clarify true risk. She emphasized the need for more precise, evidence-based approaches that reflect real-world conditions rather than fear-driven narratives.¹⁵

The takeaway is straightforward — fix the data first before drawing conclusions. Injury risk assessments should ideally reflect actual time on the field, account for roster size, and track conditioning access.

• Hormones and knee alignment may influence risk — A 2016 review published in the Journal of Orthopaedics examined proposed anatomical, hormonal, and biomechanical factors that may contribute to ACL injuries in women. It highlighted evidence showing that strong quadriceps activation during eccentric contraction plays a key role in ACL injury during high-risk movements.

The review also noted that relaxin, a hormone that softens connective tissue for childbirth, has receptors in knee ligaments. This can affect collagen turnover and cause ligament laxity throughout the menstrual cycle.¹⁶

In addition, the review pointed out gaps and inconsistent results in hormone research. It recommended improved methods for measuring exposure and cycle timing in future studies to avoid exaggerating or incorrectly assigning risks. As the authors stated:¹⁷

“Identifying sports-specific at-risk motions and positions and encouraging athletes to avoid these at-risk situations when possible seems promising. Further, strategies for activating protective neuromuscular responses when at-risk situations are encountered is also a possible prevention strategy. There is a need to improve public and participant awareness for risk of ACL injury and the possibilities for prevention.”

• Injury patterns diverged at elite competition levels — A 2015 study published in the British Journal of Sports Medicine analyzed 14 international athletics championships from 2007 to 2014 consisting of 17,592 athletes. Researchers found a higher overall injury rate in men (110.3 per 1,000 registered athletes) than in women (88.5 per 1,000).

Men also sustained more thigh strains and cramps, whereas women had more stress fractures. The authors recommend gender-specific prevention tailored to the demands of each discipline.¹⁸

• Torn ligaments — Ligaments are strong bands that hold your knee together. When one tears, like the ACL in the center of the knee, it can throw off stability. ACL injuries often happen during sudden stops, jumps, or quick pivots in sports like soccer or basketball. They’re serious and usually need months of rehab.¹⁹

• Meniscus tears — The meniscus is a cushion of cartilage between your thigh bone and shin bone. A twist or hard impact can tear it, causing pain, swelling, and sometimes a “locked” knee. If you need to use your hands to straighten your leg, that’s a red flag for a meniscus tear.²⁰

• Osteoarthritis — This is caused by wear and tear on the cartilage that protects your knee joint. Over time, the cushion thins, making movement painful and stiff. It’s common in older athletes and anyone with past injuries. Strength training and low-impact exercise can help slow it down.²¹

• Runner’s knee and iliotibial (IT) band syndrome — Runner’s knee causes pain around the kneecap, often from overuse or muscle imbalance. IT band syndrome happens when a thick band of tissue running from your hip to your shin gets tight and rubs against the knee. Both are common in runners and can be eased with stretching and proper form.²²

• Tendinitis — Also called “jumper’s knee,” this is irritation of the tendon that connects your kneecap to your shinbone. It often shows up in sports that involve a lot of jumping, like volleyball or basketball. Rest, icing, and strengthening exercises can help prevent it from becoming chronic.²³

• Excess weight or obesity — Every step you take applies about 1.5 times your body weight in pressure to your knees, and climbing stairs adds two to three times that force. Extra pounds mean extra stress and pain.²⁴

• Aging — As you age, the cartilage in your knees thins out, ligaments lose strength, and joints stiffen, reducing shock absorption. The wear and tear on your joints are significant reasons why osteoarthritis affects about 32.5 million U.S. adults, making it one of the most common causes of knee pain in older adults.²⁵

• Gender — Women are nearly twice as likely to develop knee osteoarthritis as men, partly due to wider hips, greater joint flexibility, and hormonal changes after menopause. These factors can affect knee alignment and cartilage health, increasing strain during activity.²⁶

• Overuse — Sprains and strains from repetitive knee movements account for 25% to 30% of all sports injuries. High-impact sports, frequent training, or jobs that involve kneeling can wear down cartilage and ligaments over time.²⁷

• Prior injury — A previous ACL tear or severe sprain can raise your odds of arthritis later in life. Studies show that old injuries often lead to joint instability and early cartilage breakdown.²⁸

• Contact sports — Football players face about 64.7 injuries per 1,000 athlete-exposures, many involving the knee. Quick pivots, tackles, and collisions put enormous stress on ligaments and cartilage.²⁹

• Knee surgery is on par with placebo — Arthroscopic partial meniscectomy — the most common orthopedic procedure in the U.S.³⁰ — has been under scrutiny. A Finnish study found arthroscopic surgery for degenerative meniscus tears offered no more benefit than sham surgery.³¹ A landmark 2002 trial echoed this for knee osteoarthritis.³² Worse, meniscectomy can triple the risk of future knee replacement.³³

• Physical therapy can match surgery for many — Supervised physical therapy that targets strength (especially quadriceps, hamstrings, and glutes), balance, and movement control performs as well as arthroscopic meniscus surgery for many middle-aged adults.³⁴

• Be careful with nonsteroidal anti-inflammatory drugs (NSAIDs) — NSAIDs can calm a flare, but they are not harmless. They’re known to raise blood pressure, strain the kidneys, and irritate the stomach. Long-term use may also blunt healing of tissue.

Often, ice, rest, and proper sleep can be just as effective as medication. If really needed, use the lowest effective dose for the shortest time, consider topical gels first, and avoid combining products.³⁵

1. Train your muscles to protect your knees — Strong muscles act like shock absorbers for your knees. Neuromuscular training teaches safe landing, cutting, and pivoting techniques to prevent stress on the joint. These programs use balance drills, core work, and landing practice to stop the knee from caving inward. Focus on isometric exercises like wall sits, which hold your muscles in a static position to build strength without strain.

Add moves such as straight-leg raises, squats, and sit-to-stand drills to improve stability and reduce stress on the knee. Done right, this training can cut injury risk by nearly half. Read “Knee Pain? Strength Training and Home Exercises Will Help” to learn more.

2. Pay attention to hormonal cycles — For female athletes, hormones can affect knee stability. During ovulation, the body produces more relaxin.³⁶ That extra flexibility might sound good, but it can make the knee less stable during intense activity. Plan heavy drills outside this window or focus on technique and recovery during high-risk days.

3. Maximize your workouts according to your age — Tailor your workouts to prevent injury and add resilience. Younger men benefit from adding hamstring-strength and agility drills to help protect the ACL during fast pivots and jumps. Women in midlife benefit from focusing on joint stability, low-impact strength training, and flexibility.

4. Warm up like a pro — Skipping a proper warm-up is like starting a race with untied shoes. Dynamic stretches, such as leg swings, walking lunges, and high knees, prepare muscles and ligaments for sudden moves. A good warm-up increases blood flow, improves flexibility, and reduces the risk of ACL and meniscus tears.

5. Don’t rush your return to sport or workout — After an injury or surgery, jumping back too soon can lead to an ACL retear or damage to the meniscus. Experts recommend a gradual return with strength tests, balance checks, and sport-specific drills before full play.

6. Lighten the load — If you carry extra weight, combine a healthy eating plan with regular exercise. In a 2013 trial of adults with knee osteoarthritis, those who did diet plus exercise reported less pain and better function than diet-only or exercise-only groups.³⁷

• The backbone of joint support — Collagen makes up about 30% of the protein in your body and is a key component of cartilage — the tissue that cushions your knee. As you age, collagen production slows, leaving joints less elastic and more prone to wear.

Bone broth is a natural collagen powerhouse and is packed with gelatin, glucosamine, and chondroitin, all vital for joint health. It also delivers amino acids, such as glycine and proline, which have anti-inflammatory properties that may ease pain and stiffness. For athletes, sipping bone broth can be a simple way to nourish connective tissue while staying hydrated.

• Beyond comfort food — Supplementing with high-quality collagen can help repair soft tissue and maintain flexibility. Look for organic or grass fed sources and avoid overly processed hydrolyzed forms, which may contain unwanted byproducts. Some experts recommend up to 50 grams (g) daily for active individuals.

• Protectors of your cartilage — Glucosamine and chondroitin, which are naturally found in cartilage, are often paired in supplements. Research suggests they may help slow cartilage breakdown and reduce osteoarthritis symptoms. While results vary, many clinicians still recommend them for athletes with early joint discomfort or those recovering from knee injuries.

• Swap the seed oils for healthier fats — Most processed foods and restaurant dishes use soybean, canola, corn, sunflower, and safflower oils, which are high in linoleic acid (LA), a polyunsaturated fat (PUF). Lowering LA helps reduce chronic inflammation, which can damage cartilage and worsen joint pain over time.

Keep your LA under 5 grams (g) a day; ideally less than 2 g. Nutrition apps like , my upcoming Mercola Health Coach app makes tracking easy. Healthy fats include butter, ghee, coconut oil, and beef tallow.

• Choose foods that fuel your cells — A bioenergetic diet focuses on foods that support clean glucose metabolism and healthy mitochondrial function. This helps the cells that maintain your joints — like chondrocytes in cartilage — generate energy efficiently, reducing oxidative stress that can accelerate tissue breakdown. I explore this in detail in my book, “Your Guide to Cellular Health: Unlocking the Science of Longevity and Joy.”