Back foot influence on dorsiflexion using three different positions of the weight bearing lunge test

Key points

1. 01All three back foot positions (full contact, heel raised, non-weight-bearing) produced significantly different dorsiflexion range of motion values (P<0.001) regardless of measurement tool used.
2. 02Large effect sizes were found for all back foot positions and measurement techniques (partial eta-squared 0.37 to 0.88).
3. 03Intra-rater reliability was excellent across all conditions (ICC 0.94 to 0.99).
4. 04Tape measure produced lower measurement error (SEM 0.45 to 0.81 cm) than goniometer (SEM 1.96 to 2.75 degrees) or inclinometer (SEM 2.2 to 3.0 degrees).
5. 05This was the first study to investigate how back foot position affects front foot dorsiflexion during the weight-bearing lunge test.

How it was conducted

Design

Randomised, repeated measures

Participants

52 healthy athletes (men and women) participating in cutting and pivoting sports

Back foot positions tested

(1) full heel contact with floor, (2) heel raised off floor, (3) non-weight-bearing

Measurement tools

Tape measure (toe-to-wall distance), inclinometer at tibial tuberosity, goniometer from lateral malleolus to fibula head

Analysis

One-way repeated measures ANOVA with Bonferroni post hoc adjustment; reliability by ICC and SEM

What they found

• Dorsiflexion range of motion was statistically significantly different for all three back foot positions for each measurement technique (P<0.001).
• Post hoc analysis: tape measure right, position 1 to 2 mean difference 1.51 cm (95% CI 1.17-1.76), P<0.001; position 1 to 3 mean difference 3.23 cm (95% CI 2.82-3.65), P<0.001; position 2 to 3 mean difference 1.72 cm (95% CI 1.42-2.02), P<0.001.
• Goniometer right, position 1 to 2 mean difference 2.24 degrees (95% CI 0.74-3.74), P<0.05; position 1 to 3 mean difference 5.18 degrees (95% CI 3.18-7.17), P<0.001; position 2 to 3 mean difference 2.94 degrees (95% CI 1.08-4.83), P<0.05.
• Inclinometer right, position 1 to 2 mean difference 2.94 degrees (95% CI 1.61-4.27), P<0.05; position 1 to 3 mean difference 7.45 degrees (95% CI 5.66-9.44), P<0.001; position 2 to 3 mean difference 4.62 degrees (95% CI 3.03-6.19), P<0.05.
• Intra-rater reliability ICC ranged from 0.94 to 0.99 across all positions and measurement tools.
• Tape measure SEM 0.45-0.81 cm; goniometer SEM 1.96-2.75 degrees; inclinometer SEM 2.2-3.0 degrees.

Limitations

• Sample consisted only of athletes in cutting and pivoting sports, limiting generalisability to non-sporting or clinical rehabilitation populations.
• Distance between back foot and front foot was not standardised, so the extent to which foot separation affected results in positions 1 and 2 is unknown.
• Back knee position (flexed vs extended) was not varied, meaning the independent contribution of back-knee angle to dorsiflexion measurement was not assessed.
• Only intra-rater reliability was assessed; inter-rater reliability across different examiners was not investigated.

Why it matters

For patients

Ankle dorsiflexion measurements taken during rehabilitation or screening may read differently depending on how the clinician positions the back foot, which could affect injury risk assessments or return-to-sport decisions.

For clinicians

Always document and standardise the back foot position when using the weight-bearing lunge test; results from different positions are not directly comparable and previous literature may be difficult to compare because back foot position was rarely reported.

For readers

This study fills a clear gap by showing that an unstandardised variable - back foot placement - meaningfully changes a widely used clinical measurement, with practical implications for research reproducibility.