Running is a big sport in Singapore with 34 races already scheduled for 2019. A study last year from American Journal of Sports Medicine followed 300 runners for two years and these are what they found:
#1 Most runners experienced at least one overuse running injury
Two-thirds of the runners (199 out of 300) in the study had at least one overuse running injury.
Over half of the injured runners experienced more than one injury over a two year period.
This is not good news. Overuse injuries are preventable with proper training load progression and good running technique. It seems that the understanding of what is safe, healthy running is poor.
Surprisingly (for most of us), acute injuries are not common. The most common acute injuries are trip falls (only nine out of 300 runners) and ankle sprains (also only nine out of 300 runners).
#2 The knee is the most common site of injury. Followed by the foot.
This is not surprising at all. Many injuries can present as knee pain – runner’s knee, patellofemoral pain syndrome, patella tendinitis to name a few.
For foot injuries, plantar fasciitis seems to be big among runners.
#3 Knee joint stiffness matters
The study calculated knee stiffness by measuring the change in maximum knee extension and the change in maximum knee flexion in first half of the stance phase. (Stance phase largely refers to when your foot is in contact with the ground.) Knee stiffness was found to be higher in the injured group even after accounting for body weight and training pace.
The study concluded that knee stiffness is a significant risk factor to running injury and that can reduce stride length or run on a stable (but softer) surface to attenuated ground-reaction forces and a subsequent reduction in knee extensor moments.
#4 Women are more likely to get injured than men, in some studies
Sex was also found to be a significant predictor of injury. Female runners were more likely than male runners to sustain an overuse running injury – 73% of women and 62% of men sustained at least 1 injury. Out of the 128 female runners, 27% remained injury-free during the 2-year observation period, as opposed to 38% male runners.
#5 How much you run (i.e. mileage) doesn’t make a difference
You know how people might always tell you running is bad for your knees and that you should run less? This study found running mileage to be not a predictor of injury. Both the injured and uninjured groups reported similar training regimens at baseline. On average, both groups ran 32 kilometres per week, had 11 years of running experience, and trained at a pace of 9 min/kilometre.
p.s. a new study published October 2019 found running a marathon (no less) to reverse knee joint damage!
#6 Footwear also doesn’t make a difference!
It seems our obsession with wearing the “right” shoes is misguided. The compared lightweight/minimalist shoes to stability/motion control shoes to determine if shoe type was a significant risk factor for injury.
Both the injured and uninjured groups tended to prefer lightweight/minimalist footwear by a small margin: 56% of injured runners and 59% of uninjured runners. While changes in shoe preference did occur in the first 12 months, the direction of change between groups was also not associated with injury.
#7 Flexibility – believe it or not – did not increase risk of injury.
The study measured hamstring flexibility (90:90 straight leg raise), quadricep flexibility (maximum knee flexion while facing down), and ankle flexibility (both plantar and dorsiflexion) and found that none of them were associated with an increased risk of injury!
#8 More strength doesn’t mean less injuries
After adjusting for sex, hip abductor, knee extensor and flexor, and ankle plantar flexor strengths were statistically similar between groups and not predictive of injury.
#9 your state of mind matters
While both injured and uninjured groups reported low levels of pain, above-average physical health–related quality-of-life scores, high satisfaction with life and exercise self-efficacy, and moderately low stress levels, injured runners reported significantly worse mental health related quality of life and also more negative emotions (i.e. jittery, irritable).
The authors suggest that runners experiencing more negative mood may exceed their limits or take fewer precautions with their training. While psychosocial factors are predictive of injuries in this study, more research is needed to determine how mental health affects the physiologic state of running.
So there you go. These are the nine truths we know about running injuries as of 2018. Don’t let anyone try to convince you otherwise.
- Messier SP, Martin DF, Mihalko SL, Ip E, DeVita P, Cannon DW, Love M, Beringer D, Saldana S, Fellin RE, Seay JF. A 2-Year Prospective Cohort Study of Overuse Running Injuries: The Runners and Injury Longitudinal Study (TRAILS). Am J Sports Med. 2018 Jul;46(9):2211-2221.