How Downhill and Uphill Running Interfere Posture and Muscle Activity: A Descriptive Laboratory Study.
Nadine Engeler, Eric Lichtenstein, Oliver Faude and 1 others
PMID 40756801WHAT IT FOUND
Downhill running increased lumbar lordosis and backward trunk lean, while uphill running decreased lordosis and shifted the trunk forward.
Erector spinae activity dropped on most slopes, but vastus lateralis and gastrocnemius worked harder. These changes highlight distinct biomechanical demands for trail runners.
Key findings
01Lumbar lordosis increased during downhill gradients and decreased during uphill gradients of +5% and +10% compared to level running.
02Trunk inclination shifted backward during downhill running and forward during uphill running, with effects growing as the gradient steepened.
03Erector spinae muscle activity decreased during most gradients, while vastus lateralis activity increased during downhill running and gastrocnemius activity increased during uphill running.
STILL TO COME
How it was doneWhat they foundWhat it means for PTs
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What it does not show
The study included only twelve healthy runners, so findings may not apply to individuals with low back pain or different biomechanical patterns. Lumbar lordosis was measured using skin markers, which can be affected by soft tissue movement, making absolute values uncertain. Results were obtained on a treadmill, which may not fully replicate the mechanics of overground trail running. Muscle activity was estimated from a single area using surface electromyography, which is susceptible to signal cross-talk.
Declared interests
The authors report no conflicts of interest.
The easy way to misread this
Do not assume these biomechanical changes cause injury or pain. The study measured healthy runners without symptoms, and it did not assess injury rates or pain levels. The increased lordosis and backward lean are adaptations to the gradient, not necessarily pathological signs.