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Study note

Effect of Foot Orthoses on Running Economy and Foot Longitudinal Arch Motion in Runners With Flat-Arched Feet.

PMID 33691280 (2021): foot, orthoses — Running economy (study note for endurance athletes).

Updated Feb 23, 2026

Read the study note

Study note • PMID 33691280

Effect of Foot Orthoses on Running Economy and Foot Longitudinal Arch Motion in Runners With Flat-Arched Feet.

International journal of sports physiology and performance2021 • DOI 10.1123/ijspp.2020-0717

How to use this page

This note summarizes one study record. Check the participants, methods, results, and limitations before applying it to training.

  • Design signal: randomized trial.
  • Population relevance: athlete/trained context.
  • Consistency: single-study evidence.
  • Practical recommendation depends on tolerance, context, and whether it protects training consistency.

ELI5

In plain language

To determine the effect of manipulating foot longitudinal arch motion with different-stiffness foot orthoses on running economy (RE) in runners with flat-arched feet and if changes in arch deformation… (randomized trial; recreational runners).

The abstract suggests a trade-off or negative effect affecting Running economy. Treat this as a signal, not a guarantee; confirm methods and context in the full paper.

Takeaways

What the abstract suggests

  • Study question: To determine the effect of manipulating foot longitudinal arch motion with different-stiffness foot orthoses on running economy (RE) in runners with flat-arched feet and if changes in arch deformation…
  • The abstract suggests a trade-off or negative effect affecting Running economy.
  • Population: recreational runners.
  • Protocol cues (title/abstract): 12 km.

Protocol

Protocol (as reported)

  • Intervention/exposure: foot, orthoses (vs comparison group).
  • Dose/time/duration cues in abstract/title: 12 km.
  • Outcomes: Running economy.
  • Replication note: abstracts often omit adherence and timing; confirm details before changing training or supplementation.

Fit

Who it may help, and who should be cautious

Who it helps

  • Athletes similar to the study population (recreational runners) working on biomechanics.
  • Athletes who can measure Running economy with a repeatable workout or time-trial effort.

Who should be cautious

  • If you have symptoms or conditions that make the intervention risky, get professional guidance.
  • If you’re near race day and can’t safely test, defer the experiment.

Methods

What the study actually did

  • Design: randomized trial.
  • Population: recreational runners.
  • Comparator: comparison group.
  • Outcomes measured: Running economy.
  • Protocol cues mentioned: 12 km.
  • Source: PubMed PMID 33691280 (2021) — International journal of sports physiology and performance.

Results excerpt

What the abstract reports

Compared with standard orthoses, the mean VO2submax was significantly lower in both the flexible orthoses (-0.8 mL.kg-1.min-1, P < .001, d = 0.35) and footwear-only conditions (-1.2 mL.kg-1.min-1, P < .001, d = 0.49).

Note: excerpts are short; for full context, read the paper.

Limits

Limitations and bias

  • Abstract-only summaries can miss critical details (population, protocol, adherence, and context).
  • Single studies often don’t generalize to your event, history, and training load; treat results as a starting point.
  • If your context differs (elite vs recreational; cycling vs running), adjust expectations and be conservative.
  • This is performance information, not medical advice.

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Sources