Does the Distance Between Ground Poles Affect Limb, Spinal and Pelvic Kinematics in Horses When Walking In-Hand?

Polework exercise is commonly used in equine training and rehabilitation; however, the influence of pole spacing on locomotor kinematics remains unclear. This study investigated the effects of pole spacing on limb, thoracolumbar and pelvic kinematics in horses walking in-hand. Eleven warmblood horses were assessed during overground walking and over five ground poles set at 85%, 100% and 105% of forelimb step length. Pole spacing did not significantly alter maximum fore- or hindlimb retraction; however, protraction-retraction range of motion (ROM) was reduced at 85% spacing. Forelimb ROM was reduced by 6.5% compared with 100% spacing and by 8.7% compared with 105% spacing, while hindlimb ROM was reduced by 2.9%. Hindlimb protraction was reduced at 85% compared with 100% and 105% spacing (p = 0.022, p = 0.034). Tarsal ROM increased over poles from NP: 38.0 ± 3.6°, poles: 62.1-64.2° (p < 0.001), irrespective of spacing. Walking over poles increased thoracic ROM at T10 from 7.9 ± 1.2° to 9.4-9.6° and at T13 from 8.7 ± 1.3° to 9.4-10.1° (p < 0.001), primarily through increased extension. Shorter spacing (85%) reduced T10 ROM compared with 100% spacing (p = 0.003). Changes in lumbar flexion were smaller, with significant effects observed only at L3 and L5, where maximal flexion increased from 9.6 ± 1.4° to 10.3 ± 1.8° and from 9.2 ± 1.5° to 9.9 ± 1.7°, respectively, at longer pole spacings (p < 0.05). These findings suggest that modest changes in pole spacing result in relatively small alterations in limb and thoracolumbar kinematics during walking. This should be considered when using polework in practice.