Most of the energy used when stepping over or into a hole comes from lifting and lowering your body’s center of mass—not from moving your legs back and forth.
Scientific Claim
The mechanical energy cost of transport (CoTtot) during obstacle negotiation is strongly correlated with the center-of-mass mechanical energy cost (CoTCoM), suggesting that changes in body height and movement are the primary drivers of energy expenditure in this task.
Original Statement
“CoTCoM was strongly correlated with CoTtot, both for the complete task (IN strategy r = 0.98, p < 0.001; OVER strategy r = 0.92, p < 0.001) and for individual steps (IN strategy r = 0.99, p < 0.001; OVER strategy r = 0.94, p < 0.001).”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
definitive
Can make definitive causal claims
Assessment Explanation
This is a direct statistical correlation from biomechanical measurements with high precision (r > 0.92, p < 0.001), and the authors correctly report it as a correlation, not causation.
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.
Randomized Controlled TrialLevel 1aThat artificially constraining center-of-mass vertical displacement reduces total mechanical energy cost proportionally during obstacle negotiation.
That artificially constraining center-of-mass vertical displacement reduces total mechanical energy cost proportionally during obstacle negotiation.
What This Would Prove
That artificially constraining center-of-mass vertical displacement reduces total mechanical energy cost proportionally during obstacle negotiation.
Ideal Study Design
A within-subject RCT with 30 healthy adults performing IN and OVER strategies while wearing a harness system that limits vertical CoM displacement by 20–50%, measuring changes in CoTtot and CoTCoM via motion capture and force plates.
Limitation: Harness may alter natural gait mechanics or introduce compensatory movements.
Cross-Sectional StudyLevel 3That individuals with greater CoM displacement during obstacle negotiation have higher metabolic cost, even when mechanical work is matched.
That individuals with greater CoM displacement during obstacle negotiation have higher metabolic cost, even when mechanical work is matched.
What This Would Prove
That individuals with greater CoM displacement during obstacle negotiation have higher metabolic cost, even when mechanical work is matched.
Ideal Study Design
A cross-sectional study of 40 adults with varying body mass index (BMI) performing identical obstacle traversals, measuring both mechanical work (CoTtot/CoTCoM) and metabolic cost via indirect calorimetry to test if CoM displacement predicts metabolic cost beyond mechanical work.
Limitation: Cannot disentangle effects of body size from movement efficiency.
Evidence from Studies
No evidence studies found yet.