The transition from winter to spring can be a difficult time of year to get out of the house for a run. Rainy, cold days can lead us to opt for a run on the treadmill rather than braving the elements for a long run outside. The question becomes how different is running on a treadmill versus running over ground? Today we are going to be discussing a recent research article looking at different forces through the knee and ankle when running on treadmill versus running over ground.
Knee pain, specifically patellofemoral pain, and achilles tendon injuries are two of the most common injuries sustained by runners. Patellofemoral pain occurs due to an increased load between your kneecap and your femur. This can cause pain with prolonged sitting, climbing stairs, or standing up from a seated position. Achilles tendon injuries are often associated with overuse, and can be painful with push off while running/walking or going up a hill. These injuries can be lingering issues for runners, and if left untreated, can be very painful, often resulting in an inability to run. This study evaluated the different stresses placed on these two areas between running on a treadmill and overground.
Previous studies have shown that when running on a treadmill, runners tend to adopt a 1 to 5 percent shorter step rate compared to their selected step rate on ground. An increase in step rate has also been shown to decrease patellofemoral stress while running. This helps to limit stride length, decreasing the tendency to overstride. The research showed no difference between patellofemoral stress on the treadmill versus overground running. This was not the case for the achilles tendon loads. Running on a treadmill produced a higher loads sustained through the tendon, meaning that the calf muscles are working much harder when running on a treadmill. Further studies are needed to determine how this may impact injury rates for those who prefer to run on treadmills, and how this information can be utilized for returning from injury.
As April showers turn into May flowers, it is good to get out on the road and leave the treadmill behind. For those runners who have been experiencing pain in their achilles, or even knee pain, please contact your local Breakthru Physical Therapist to help you get back to running pain free.
-Dr. Dan Pinto PT, DPT
Williy R. et al. Patellofemoral Joint and Achilles Tendon Loads During Overground and Treadmill Running. JOSPT 2016. 46:8.