# Biomechanical comparison of pin and freeride ski mountaineering bindings in recreational skiers

## TL;DR

This study compared how two types of ski mountaineering bindings affect the movement of recreational skiers uphill, finding small biomechanical differences that likely don't impact performance.

## Contribution

The study is the first to compare lower-body kinematics between pin and freeride bindings in recreational skiers across different grades.

## Key findings

- Freeride bindings showed greater ankle, knee, and hip flexion near toe-off compared to pin bindings.
- Freeride bindings resulted in slower cycle rates, longer cycle lengths, and higher step heights.
- Differences in biomechanics were statistically significant but small in magnitude and unlikely to affect performance.

## Abstract

Although increased equipment weight is known to increase the metabolic cost of uphill skiing at a constant grade, the effects of different binding types on ski mountaineer kinematics across varying grades remains unknown. This study compared lower-body kinematics in recreational skiers between those using pin bindings and those using freeride bindings.

Sixteen participants skied on a treadmill using either pin or freeride bindings mounted to matching skis during 3-min stages at grades of 8% and 15%. Kinematic data were recorded during the final 30 s of each stage. Sagittal-plane joint angles of the lower limbs and torso, along with cycle metrics, were compared across conditions using statistical parametric mapping and linear mixed-effects models.

Compared with pin bindings, freeride bindings showed greater ankle plantarflexion (p = 0.05), knee flexion (p = 0.02), and hip flexion (p = 0.05) near toe-off, although the magnitudes of these differences were small. Freeride bindings also resulted in slower cycle rates (p < 0.001, d = 0.34), longer cycle lengths (p < 0.001, d = 0.36) and cycle times (p < 0.001, d = 0.36), and higher step heights (p < 0.001, d = 0.32); however, all differences were small in magnitude and effect size.

These findings suggest that while biomechanical differences between binding types are statistically significant, their small differences and effect sizes are unlikely to have practical relevance for uphill travel performance in recreational skiers under laboratory settings.