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

Overview

• This study examined how different distances between ground poles affect the movement patterns of limbs, spine, and pelvis in horses walking in-hand.
• The research found that variations in pole spacing caused only minor changes in horse locomotion, especially concerning limb motion and spinal flexibility.

Background and Purpose

• Polework—walking horses over ground poles—is common in horse training and rehabilitation to improve coordination and strength.
• However, it was unclear how varying the spacing between these poles influences the biomechanics of horse movement, particularly in limbs, spine, and pelvis.
• The study aimed to fill this gap by measuring kinematic parameters while horses walked over poles set at three spacings related to their forelimb step length: 85%, 100%, and 105%.

Participants and Methodology

• Eleven warmblood horses participated in the study.
• They were walked overground and over a series of five ground poles arranged at three different spacing configurations: 85%, 100%, and 105% of the horse’s forelimb step length.
• Researchers recorded limb protraction (forward movement) and retraction (backward movement), range of motion (ROM) in different joints, as well as thoracic, lumbar, and pelvic spine movements using kinematic analysis tools.

Key Findings on Limb Kinematics

• Pole spacing did not significantly change the maximum limb retraction in forelimbs or hindlimbs.
• However, the overall fore- and hindlimb protraction-retraction ROM was reduced at the shortest spacing (85%).
• Specifically, forelimb ROM was 6.5% less than at 100% spacing, and 8.7% less than at 105% spacing; hindlimb ROM was 2.9% less.
• Hindlimb protraction, or the forward reach of the hindlimb, decreased at 85% spacing compared to the longer spacings, indicating somewhat restricted limb movement at closer pole spacing.
• Tarsal (hock) joint ROM was significantly increased when walking over poles compared to no poles, regardless of spacing (increased from approx. 38° without poles to 62-64° with poles).

Key Findings on Spinal and Pelvic Kinematics

• Walking over poles increased the range of motion in the thoracic spine, particularly at vertebrae T10 and T13, mainly through increased extension movements.
• Shorter pole spacing (85%) led to reduced ROM at T10 when compared to 100% spacing, showing spacing can mildly influence spinal flexibility.
• Changes in the lumbar spine were subtler; only at vertebrae L3 and L5 did longer pole spacings increase maximal flexion angles by small margins (approx. 0.7° increases).
• Overall, modest changes in pole spacing did not cause major alterations in pelvic or lumbar spinal movement during walking.

Conclusions and Practical Implications

• Changing pole spacing within a modest range (85% to 105% of step length) results in only small changes in horse limb movements and spinal kinematics during walking.
• Using poles spaced too close (85%) slightly restricts limb protraction and reduces some spinal movement, which might be relevant when training or rehabilitating horses with mobility issues.
• The increased joint and spine movements observed when walking over poles (compared to no poles) supports that polework can enhance mobility and coordination.
• Trainers and therapists should consider these minor biomechanical effects when designing pole exercises to optimize efficacy and safety.