Switching from a heel strike to a forefoot strike shifts load from the knee to the ankle, calf and Achilles, without improving running economy or proven injury reduction
Interpretation
Biomechanics are consistent: a meta-analysis of 53 studies (Anderson 2020) and lab studies in 38 women (Kulmala 2013: Achilles force 6.3 vs 5.1 body weights, patellofemoral force 4.3 vs 5.1) and 16 men (Stearne 2014: ankle internal rotation moment +33%, total positive power +17% when switching) show forefoot striking moves load from knee to ankle. Economy evidence is consistent but small: no difference between habitual patterns and worse economy when heel strikers switch (Anderson 2020; Gruber 2013, 37 runners). Injury evidence is weak: only retrospective data, such as about twice the repetitive stress injury rate in 36 rearfoot vs 16 forefoot collegiate runners (Daoud 2012). Most recreational runners heel strike (88.9% of 936; Larson 2011). Gaps: small single-sex samples, short tests, no triathletes, no prospective injury trials.
Practical implication
Uninjured heel strikers have no evidence-based reason to change footstrike over winter; the change adds calf and Achilles load and may cost economy. A deliberate change, if advised for a specific problem such as knee pain, should be gradual and paired with calf strengthening. Based on lab and retrospective data, not triathletes.
Sources
7 sources, independently verified.
53 studies. Injury: only retrospective evidence (non-rearfoot linked to lower reported repetitive stress injury); no prospective comparisons, so the link can't be determined. Economy: no difference between habitual rearfoot and non-rearfoot runners at slow, moderate or fast speeds; immediately switching rearfoot runners to non-rearfoot reduced economy at 10.8 and 12.6 km/h. Biomechanics: non-rearfoot running lowers vertical loading rates, knee flexion and patellofemoral stress (limited evidence) and raises peak ankle plantarflexor moment. Changing strike pattern cannot be recommended for an uninjured rearfoot runner.
Review of the three main reasons given for switching from rearfoot to mid/forefoot striking: switching does not improve running economy, does not eliminate the impact peak, and has not been shown to reduce running injury risk. Rearfoot striking is clearly the more prevalent pattern.
At 10 km, 88.9% rearfoot, 3.4% midfoot, 1.8% forefoot and 5.9% asymmetric. Rearfoot striking increased by 32 km, with many midfoot/forefoot strikers switching to the heel. Footstrike was not related to marathon finishing time.
Treadmill running at 3.0, 3.5 and 4.0 m/s in habitual and alternate patterns. No difference in oxygen uptake between groups in habitual patterns; at the fast speed oxygen uptake was greater with the forefoot pattern. Concluded the forefoot pattern is not more economical than the rearfoot pattern.
At 4 m/s, forefoot strikers had lower patellofemoral contact force (4.3 vs 5.1 body weights) and frontal-plane knee moment (1.49 vs 1.97 N·m/kg), but higher ankle plantarflexor moment (3.12 vs 2.54 N·m/kg) and Achilles tendon force (6.3 vs 5.1 body weights). Injury risk not measured; women only.
At 4.5 m/s, habitual rearfoot runners imposing a forefoot strike increased ankle internal rotation moment by 33% and total positive lower-limb average power by 17%, without reducing knee abduction moment to habitual forefoot levels. Total lower-limb work and power did not differ between habitual groups. No clear overall mechanical advantage for either pattern; switching shifts loading between joints. Sample size and sex from a published literature review of the paper.
Retrospective injury records: about 74% had a moderate or severe injury per year; rearfoot strikers had about twice the rate of repetitive stress injuries; traumatic injuries did not differ. Sex, distance and weekly mileage were also associated with injury. Mechanism untested; one team.