04/18/2026
The long-term risk of concussion is not only what can go on in the brain and how this can change how we think act react, sleep, socialize process thoughts and behaviors, but it can also have a significant end catastrophic impact on potential orthopedic injuries, such as tears of the hip labrum, tears of the meniscus and the ACL, foot and ankle dysfunction and anything up and down that entire chain of motion.
Ignoring a concussion is a mistake 100% of the time!!!
Multiple studies, including systematic reviews and meta-analyses, have identified a consistent association between a history of concussion(s)—particularly multiple concussions—and an elevated risk of subsequent orthopedic (musculoskeletal) injuries, most commonly lower extremity (LE) injuries such as ankle sprains, knee sprains, ACL injuries, and foot injuries in athletes.26
This risk appears dose-dependent in several cohorts (higher with multiple prior concussions) and is most pronounced in the weeks to months after return to play (RTP), though it can persist up to 1–2 years. The association holds across high school, collegiate, and professional levels, with proposed mechanisms involving lingering deficits in neuromuscular control, balance, proprioception, and sensorimotor integration—even after clinical concussion symptoms resolve.40
Below is a summary of key high-quality evidence (focusing on peer-reviewed systematic reviews/meta-analyses and large cohort studies that directly address multiple concussions or dose-response effects). I prioritized studies reporting odds ratios (OR), relative risks (RR), incidence, and time frames relevant to orthopedic injury risk.
Systematic Reviews and Meta-Analyses (Broad Evidence Base)
• Reneker et al. (2019): Systematic review and meta-analysis of athletes and military personnel. A history of concussion was associated with significantly increased odds of all subsequent injuries (OR = 2.55; 95% CI 1.85–3.52), recurrent concussion (OR = 3.73; 95% CI 2.41–5.78), and lower extremity injuries specifically (OR = 1.60; 95% CI 1.32–1.94). Risk was evident in both time-to-event and injury-rate analyses.01
• McCann/Ramirez et al. (2022): Systematic review and meta-analysis focused on college athletes. History of concussion conferred a 58% greater risk of LE musculoskeletal injury (RR = 1.58; 95% CI 1.30–1.93). Subgroup analysis showed the risk was highest in the first 90 days post-RTP (RR = 2.20; 95% CI 1.58–3.05) but attenuated (non-significant) at 1 year (RR = 1.26; 95% CI 0.98–1.61).226
• Liao et al. (2025): Recent meta-analysis of 19 cohort studies (86,879 athletes). History of concussion increased odds of all-cause injury (OR = 1.93; 95% CI 1.39–2.68), recurrent concussion (OR = 3.06; 95% CI 1.81–5.17), upper extremity injury (OR = 1.76), and LE injury (OR = 1.49; 95% CI 1.06–2.09). Risk was strongest in collegiate athletes and with longer follow-up (>6 months). Heterogeneity was high, so results reflect average associations.630
Studies Specifically Addressing Multiple Concussions (Dose-Response)
Several cohort studies directly compared multiple concussions (MC) vs. single concussion (SC) vs. no concussion (NC) and found elevated orthopedic risk with MC:
• Harada et al. (2019): NCAA Division I athletes (48 MC athletes matched by s*x, sport, position, and games played to SC and NC controls). After RTP from the index concussion, LE injury incidence was significantly higher in the MC group (75%) than SC (52%) or NC (56%) (P = 0.049). Odds of LE injury were 3.0 times higher in MC vs. SC (OR 3.00; 95% CI 1.26–7.12; P = 0.01) and 1.66 times higher vs. NC (OR 1.66; 95% CI 1.07–2.56; P = 0.02). Time to first LE injury was also significantly shorter in the MC group (P = 0.01). No difference was seen between SC and NC. The authors suggested possible persistent neuromuscular deficits or inherent injury-prone traits in the MC cohort, warranting stricter RTP protocols.1845
• Baker et al. (2022): NFL players (single and multiple concussion cohorts vs. age/position-matched NC controls). Both SC and MC groups had significantly elevated odds of LE injury post-RTP compared with NC (SC: OR 2.28; MC: OR 2.92). There was no significant difference in odds between SC and MC (OR 1.00), but time to LE injury was significantly shorter in the SC group vs. MC within 1 year (P = 0.01).19
• Jildeh et al. (2022): Systematic review of LE injury after sports-related concussion. Confirmed elevated risk post-RTP (within 90 days and 1 year). Noted a stepwise increase in risk with multiple concussions (e.g., OR 2.29 for ≥2 concussions in some included data).1422
Dose-Response in Younger Athletes
• Lynall et al. (2017): High school athletes (data from 18,000+ athletes across 27 sports). For every previous concussion, the odds of a subsequent time-loss LE injury increased 34% (OR = 1.34; 95% CI 1.13–1.60). No significant effect was seen for any LE injury or non–time-loss injuries. This suggests concussion history selectively elevates risk for more severe orthopedic injuries in adolescents.2446
Additional Supporting Evidence
• Herman et al. (2017): Collegiate athletes; concussed group had 3.39 times higher odds of LE injury within 90 days post-RTP vs. matched controls (50% vs. 20% incidence).33
• Woodrow et al. (2025): Large cohort (>899,000 athletes); post-concussion increases in specific LE orthopedic injuries within 1 year, including ankle sprain (RR 1.18), unspecified ankle injury (RR 1.40), knee sprain (RR 1.36), and MCL sprain (RR 1.23).23
Key patterns across studies: Risk is often highest acutely (first 90 days post-RTP) but can persist; it is stronger for time-loss/severe injuries; and MC may confer additional risk compared with SC in collegiate cohorts. Limitations commonly noted include heterogeneity in injury definitions, follow-up duration, and potential confounding (e.g., playing style or prior injury history).
These findings are highly relevant particularly in sports medicine and return-to-sport protocols for athletes with concussion history. Screening for neuromuscular deficits (e.g., balance, gait, landing mechanics) and targeted interventions may help mitigate orthopedic injury risk
