A 2-Year Prospective Cohort Study of
Overuse Running Injuries: The Runners and Injury Longitudinal Study (TRAILS).

Messier SP, Martin DF, Mihalko SL, Ip E, DeVita
P, Cannon DW, Love M, Beringer D, Saldana S, Fellin RE, Seay JF. Am J Sports
2018 May
1:363546518773755. doi: 10.1177/0363546518773755. [Epub ahead of print]

Take Home Message:
Among recreational runners, females and those with greater knee stiffness
(often runners with a higher body mass) were more likely to develop overuse
injuries.  Many long-established factors (e.g.,
arch height, Q-angle) had no relation with new overuse injuries. 


While running is a popular
form of physical activity, the causes of running injuries remain a mystery. Very
few researchers have followed runners over a long time and completed a
comprehensive assessment of risk factors. Therefore, the authors undertook a
prospective study to identify risk factors associated with running-related overuse
injuries. The authors recruited 300 active recreational runners who ran 5-100
miles/week, with an average of 11 years running experience. At the start of the
study, participants provided information regarding training behaviors and
completed physiologic testing (i.e., flexibility, arch height, Q-angle,
strength) and a biomechanical gait assessment. They also completed
questionnaires on psychosocial factors (i.e., self-efficacy, mental and
physical quality of life, life satisfaction, positive or negative affect,
anxiety, and pain). The authors then followed the runners for 2 years. Runners
completed biweekly surveys to disclose any injuries and changes to training or
footwear. They also completed questionnaires at 6- and 12-months. When a runner
reported an injury, they were seen by the study physician and physical
therapist. The authors to conclude three main results: 1) women were more likely
to have an overuse injury than men (73% and 62%, respectively); 2) runners with
higher body mass (>80kg) tended to have greater knee stiffness while
running, which increased the odds of having an overuse injury; and 3) lower
extremity strength and flexibility, arch height, Q-angle, rearfoot motion,
weekly mileage, footwear, and previous injury were not major factors
contributing to running-related overuse injury. Additionally, injured runners
reported worse mental health-related quality of life and more negative emotions
at baseline than runners who remained injury free. However, this relationship
did not stay significant after adjusting for other factors and likely doesn’t
directly influence injury risk.

The complex causes of
running-related overuse injuries have perplexed clinicians and researchers
alike for decades. Some long-established factors (previous injury history,
weekly mileage, footwear, strength and flexibility) were unrelated to new
overuse injury. Concentric hip, knee, and ankle weakness are highly debated
injury risk factors in runners. The investigators reported no relationship
between these risk factors and overuse injury. They suggested that rather than
strength, neuromuscular control may contribute to injury; however, this
hypothesis needs to be tested. The differences between the injured and
uninjured runners regarding baseline mental health-related quality of life is interesting
because it may shed light on the contribution of mental health on the overall
physical health of active individuals. The authors acknowledge more research is
needed to further understand how psychological factors relate to physical injury.
Overall, the authors could only account for 12% of the variance to predict
injury, which indicates there are other unidentified factors contributing to
these injuries. The authors think injured runners are unable to withstand the
repetitive and increased loads sustained while running thus “overwhelming the
tissues’ resiliencies.” However, measuring tissue physiology is not an easy
feat, thus the influence of this remains unknown. A major limitation of this
study is the lack of re-assessment of any biomechanical or physiological
measurements, which could have provided further insight into the multifactorial
nature of risk factors for sustaining a running related injury. In the
meantime, clinicians should perform pre-injury screenings on at-risk female
runners or individuals with a body mass >80kg and monitor their
progress during training to catch any inclinations of overuse injury

Questions for Discussion:
Do you take into consideration psychological factors in addition to
physiological mechanisms when designing a treatment plan for injured runners?
Should we stop assessing a runners’ baseline concentric strength and solely
focus on neuromuscular control?

Written by: Danielle M. Torp
Reviewed by: Jeffrey