Running continues to grow in popularity as one of the most accessible and effective forms of physical activity for improving cardiovascular health and overall wellness. However, the risk of running related injuries remains a significant concern, with incidence rates ranging from 19% to 79% depending on the population studied. Understanding the risk factors for running injuries helps runners make informed decisions about training, equipment and injury prevention strategies. Two recent systematic reviews examining foot strike technique and general risk factors for running injuries provide valuable insights into what predisposes runners to lower extremity injuries.

Understanding Running Injury Risk

Running injuries primarily result from overuse rather than acute trauma. The repetitive impact forces experienced during running create cumulative stress on muscles, tendons, ligaments and bones of the lower extremities. When the tissue cannot adequately recover between training sessions or when loading exceeds tissue capacity, injuries develop. The knee represents the most common injury location, with incidence ranging from 7.2% to 50% across studies. Other frequently injured areas include the lower leg, foot, upper leg, ankle, hip and pelvis, with lower back injuries occurring less commonly.

The multifactorial nature of running injuries makes identifying clear risk factors challenging. Personal characteristics like age, sex and biomechanical factors interact with training variables such as weekly mileage, running frequency and surface type. Previous injury history and lifestyle factors further complicate the picture. Recent systematic reviews synthesizing evidence from longitudinal cohort studies help clarify which factors demonstrate consistent associations with injury risk.

Foot Strike Technique and Injury Risk

One systematic review specifically examined whether foot strike technique at initial ground contact relates to running injuries. The review identified 13 studies exploring this relationship, including both categorical measures like foot strike pattern and continuous measures such as foot contact angle and strike index. The review found very low quality evidence for a relationship between foot strike technique and running injuries overall.

When examining categorical foot strike patterns specifically, two thirds of studies found associations between rearfoot striking and injury. Three studies reported significantly higher retrospective injury rates in rearfoot strikers compared with midfoot or forefoot strikers. However, one study found Achilles tendon injuries occurred more frequently in midfoot strikers, while posterior shank injuries were more common in forefoot strikers. These contradictory findings highlight the complexity of the relationship.

For continuous measures of foot strike technique including foot contact angle, ankle flexion angle and strike index, only one of seven studies reported a significant relationship with running injuries. This study found runners with current knee injuries demonstrated lower foot contact angles compared with uninjured controls, suggesting a more midfoot landing pattern potentially adopted as a compensatory strategy to reduce knee loading.

The limited and conflicting evidence reflects several methodological challenges. Most studies examining categorical foot strike patterns used retrospective designs, making it impossible to determine whether observed foot strike characteristics preceded injuries or resulted from compensatory adaptations. Small sample sizes, varying definitions of injury, and different methods for classifying foot strike technique further complicate interpretation. Many studies analyzed only five foot strikes per runner, which may not accurately represent typical foot strike patterns given within runner variability. The review concluded that while two thirds of categorical studies found relationships between foot strike pattern and injury, the very low quality of these studies prevents drawing strong conclusions.

General Risk Factors for Running Injuries

A broader systematic review examining risk factors for running injuries included 15 longitudinal cohort studies investigating personal factors, training variables and health and lifestyle factors. The review found strong evidence that previous injury represents a significant risk factor for running injuries, with four high quality studies consistently demonstrating this association. The relationship appeared especially strong in men, while studies of female novice runners with limited injury history showed less consistent associations.

The finding that previous injury predicts future injury raises important questions about injury definition and recovery. Studies varied in how they defined previous injury regarding timing, location and whether complete recovery had occurred. Incomplete healing, uncorrected biomechanical problems or recall bias may all contribute to the observed relationship. Future research should more carefully define previous injury characteristics and recovery status to better understand this association. The studies also found moderate evidence that using orthotics or shoe inserts increases injury risk. Two high quality studies demonstrated this surprising finding, which contradicts the common practice of prescribing orthotics to compensate for biomechanical deficiencies. The relationship may reflect confounding, where runners more prone to injury receive orthotic interventions, rather than orthotics themselves causing injuries. However, the finding raises questions about whether compensating for biomechanical variations actually prevents injuries.

For other potential risk factors, evidence remained limited or conflicting. One high quality study found men face higher injury risk than women overall, with younger men under 40 years particularly vulnerable. Training load and weekly running distance showed complex relationships with injury, with both very low frequency and very high weekly mileage associated with increased risk in some studies. Running experience appeared protective, though one study found runners with less than one year experience faced lower risk, while another found those with less than two years experience showed higher risk.

Sex Differences in Running Injury Risk

Five high quality studies analyzed risk factors separately for men and women, allowing examination of sex specific injury profiles. Calculating sex ratios for various risk factors revealed interesting patterns. Women demonstrated lower overall injury risk compared with men, consistent with one high quality study finding men experienced significantly more running injuries than women.

However, specific risk factors showed different associations in men versus women. Factors associated with greater injury risk in women included older age, previous participation in non axial loading sports like swimming and cycling, marathon participation in the previous year, running on concrete surfaces, longer weekly running distances between 30 and 39 miles, and wearing running shoes for four to six months. These factors showed sex ratios above 1.25, indicating meaningfully higher risk for women.

Conversely, factors showing greater injury risk in men included restarting running after a break, having a history of previous injuries, running experience of less than two years, weekly running distance between 20 and 29 miles, and running more than 40 miles weekly. These factors demonstrated sex ratios below 0.75, indicating substantially higher risk for men compared with women.

The sex differences may reflect anatomical and physiological variations between men and women, different training patterns, or varying responses to specific training stressors. However, the small number of studies examining sex specific risk factors and their generally low quality limits confidence in these findings. More high quality prospective studies analyzing men and women separately are needed to establish reliable sex specific risk profiles.

Methodological Considerations and Future Research

Both systematic reviews identified significant methodological limitations in the existing research on running injury risk factors. The lack of a standardized injury definition represents a major challenge, with studies varying in whether they require time loss from running, healthcare consultation or simply the presence of pain. Follow up periods ranged from one month to one year and methods for assessing exposure varied widely. These inconsistencies make comparing findings across studies difficult and may explain some of the conflicting results.

The predominance of retrospective study designs, especially for research on foot strike patterns, creates uncertainty about temporal relationships between risk factors and injuries. Prospective cohort studies with larger sample sizes, standardized injury definitions and careful assessment of potential confounding factors are needed. Studies should also examine specific injury types rather than combining all running injuries, given that different pathologies likely have distinct risk profiles.

Injury prevention research must also consider the multifactorial nature of running injuries. Future studies should examine how risk factors interact rather than treating them as independent predictors. For example, training load effects may differ depending on running experience, previous injury history or biomechanical characteristics. More sophisticated analytical approaches accounting for these interactions would provide more actionable insights for injury prevention.

Practical Implications for Runners

Despite the limitations in current evidence, several practical recommendations emerge from this research. Runners with a history of leg injuries should recognize their elevated risk and consider graduated return to running protocols, strength training to address potential weaknesses and close attention to training load management. Working with healthcare professionals familiar with running injuries may help identify and address factors that contributed to previous injuries.

While evidence on foot strike patterns remains inconclusive, runners should avoid making dramatic changes to their natural running mechanics without professional guidance. The lack of strong evidence for foot strike modification as an injury prevention strategy suggests that other approaches like appropriate training progression, adequate recovery, and strength training may be more beneficial. Runners experiencing persistent pain should seek evaluation rather than attempting major technique changes on their own.

Training progression deserves careful attention given the complex relationships between training load and injury risk. Both insufficient and excessive training volumes appear problematic. Novice runners should follow structured progression programs rather than rapidly increasing mileage. More experienced runners need to balance the training stimulus required for performance improvement with adequate recovery to prevent overuse injuries. Weekly increases in mileage should generally remain modest, typically no more than 10% per week, with periodic recovery weeks at reduced volume.

The finding that orthotic use associates with higher injury risk warrants reconsideration of routine orthotic prescription for injury prevention. Rather than assuming biomechanical variations require correction, a more nuanced approach considering individual circumstances seems appropriate. Runners without injury history may not benefit from orthotic interventions, while those with specific diagnosed conditions might find them helpful as part of comprehensive treatment.

Conclusion

Current evidence suggests that previous injury and orthotic use represent the most consistent risk factors for running injuries, though both findings require cautious interpretation. The relationship between foot strike technique and injury remains unclear, with very low quality evidence preventing strong conclusions. Sex differences in injury risk profiles appear to exist, but more high quality research examining men and women separately is needed to establish reliable sex specific recommendations.

The multifactorial nature of running injuries and methodological limitations in existing research highlight the need for more rigorous prospective studies with standardized definitions, adequate follow up periods, and comprehensive assessment of potential risk factors. Until stronger evidence emerges, runners should focus on gradual training progression, adequate recovery, maintaining overall fitness and strength, and seeking appropriate care when pain develops. Understanding that running injuries result from complex interactions between training load, tissue capacity, and individual characteristics can help runners make informed decisions about their training and injury prevention strategies.

References

1. Burke A, Dillon S, O’Connor S, Whyte EF, Gore S, Moran KA. Risk Factors for Injuries in Runners: A Systematic Review of Foot Strike Technique and Its Classification at Impact. Orthop J Sports Med. 2021;9(9):2325.
2. van der Worp MP, ten Haaf DSM, van Cingel R, de Wijer A, Nijhuis-van der Sanden MWG, Staal JB. Injuries in Runners; A Systematic Review on Risk Factors and Sex Differences. PLoS One. 2015;10(2):e0114937.