REPOSTED FROM ORTHOPEDICS THIS WEEK.
TRACEY ROMERO • WED, NOVEMBER 4TH, 2020
The role of shoe cushioning in preventing or exacerbating runner’s injuries has been the subject of innumerable books and heated debate. A new study from the Luxembourg Institute of Health and the Decathlon SportsLab has published a paper which provides evidence that runners with less cushioning in their running shoes have a higher risk of injury.
“As running is a popular sport, we are pleased to be able to contribute to the clarification of risk factors for running-related injuries through this study,” said Laurent Malissoux of the Physical Activity, Sport & Health research group at the Luxembourg Institute of Health in Luxembourg City.
The researchers also discovered that the mass of the athlete does not affect the risk of injury. There was no significant association between body mass index (BMI) or body fat percentage and risk of injury.
Interestingly though, lighter weight runners in the study were more at risk of injury with stiff shoes than their heavier counterparts.
They added that “no such effect was observed in heavier runner’s contrary to what one would normally expect.”
The researchers explained that this shows that lighter runners need more shock absorbing footwear.
They also wrote that “the maximum vertical impact force during running, generally considered to be a risk factor for injury, was higher in the group running with softer version than in the comparison group.”
The running biomechanics tests, however, didn’t reveal any differences in the impact load between the two types of shoes. Therefore, they said, the benefit of increased cushioning isn’t due to a decrease in impact force and loading rate.
The randomized controlled trial involved 848 healthy recreational runners. The shoes worn in each group only differed in cushioning properties. The participants were tested at their running speed on a treadmill equipped with force plates at the beginning of the study, and then they were asked to continue their usual running practices for six months and to record all training activity.
The runners covered 220,014 km over six months and completed 24,170 race sessions. The average body mass was 78.2 kg (170.4 pounds) in men and 62.8 kg (138.4 pounds) in women. Over a six month period, 128 participants (15%) reported at least one running-related injury. There was an incidence rate of 5.7 injuries per 1,000 hours of running. Ankles (26%), knees (22%) and lower legs (18%) were the most affected. Tendon inflammation (48%) and muscle injuries (19%) were the most common.