FUNCTIONAL EVALUATION USING ENHANCED TECHNIQUES FOR PRECISION IMAGING IN CLIMBING SHOES (FEETPICS)

Abstract

INTRODUCTION

Rock climbers have an elevated prevalence of foot pathology. However, the factors that may explain the association between rock climbing or climbing shoes and foot joint pathology have not been elucidated. Imaging of feet in climbing shoes is limited, and no imaging of feet engaged in rock climbing exists.

OBJECTIVE

To compare the foot joint positions of rock climbers’ feet while in climbing shoes in a weight-bearing standing position with the foot joint position when climbing on a wall.

METHODS

Recreational rock climbers (n=24; 66.7% men) from the Kansas City area were recruited. Survey data were collected on climbing habits and street/climbing shoe usage. Participants feet were imaged while in climbing shoes using a Planmed XFI weight-bearing CT (WBCT) in a standing position and again while engaged on a gym-style rock climbing wall inside the WBCT gantry. Joint angles were measured for hallux valgus angle (HVA), interphalangeal angle (IMA), and first intermetatarsal angle (IPA). HVA and IMA were selected due to a clinical correlation with hallux valgus deformity which is common among rock climbers. Statistical testing on the join angulation data was performed using a linear mixed effects regression where the position (standing or climbing) was a fixed effect, and the participant ID and participant-foot interaction were random effects.

RESULTS

Participants’ mean±SD age was 36.0±10.8 years, BMI was 24.8±4.2 kg/m², and reported climbing 2.8±1.1 times per week for 7.1±4.9 hours per week. Duration of climbing experience was 6.1±4.1 years (range: 1–15 years). Participants were comfortable climbing mean indoor bouldering V4.3±1.5 on the vermillion scale and climbing mean indoor sport 5.1±1.0 on the Yosemite decimal system. Participants indicated the hardest indoor bouldering route accomplished was V5.9±2 on the vermillion scale. The hardest indoor sport climb was 5.11±0.99 on Yosemite decimal scale. Median measured climbing shoe size was smaller than reported street shoe size (EU 41 vs 42.5, p<0.001). Compared with when standing (20.2±6.9°), there was no difference in hallux valgus angle (HVA) when climbing (HVA 20.5±7.8°; p = 0.7665). There was greater intermetatarsal angle (IMA) when climbing compared to standing (11.6±2.2° vs 9.9±1.6°; p < 0.0001). The interphalangeal angle (IPA) was greater when climbing, compared to when standing (18.7° vs 15.3°; p = 0.0009).

CONCLUSION

Using WBCT allowed a 3D weight-bearing examination of the foot structural anatomy while standing and engaged on rock-climbing footholds. Climbing shoes induce excessive angulation of the joints, more so when engaged in climbing. Additional research is needed to evaluate the effect of rotatory changes in the first ray on the development of hallux valgus and changes in sesamoid posture.