Compensatory lameness, What is it?

This paper is a technical analysis of horses with naturally occurring lameness that supports the idea of compensatory lameness often present. Note we are talking about lameness in a front and rear leg and not lameness involving two fronts or two rear legs. But what is this compensatory lameness? It is often misunderstood. In the past it was argued this meant that lameness in one limb often led to “pain” in another leg. As we understand compensatory lameness now it means that pain (the primary lameness) in one limb can cause asymmetries in the way the other limbs move that are not due to pain (secondary lameness). And even more helpful, the pattern of asymmetry helps locate which is the leg with the primary lameness.

If you have a concurrent front and rear leg lameness you may only have one painful leg with a compensatory second leg lame and the pattern may point you to which leg is painful. There are two types of asymmetries seen: ipsilateral lameness patterns and contralateral lameness patterns:

• If the fore and rear on the same side of the horse both appear to be lame leg this is a ipsilateral pattern.
• If the fore and rear diagonal legs are lame this is a contralateral pattern.

If the lame legs are ipsilateral it suggests a primary hindlimb lameness. If the lame legs are contralateral it suggests a primary front limb lameness.

Upper body movement analysis of multiple limb asymmetry in 367 clinically lame horses
Equine Vet J. 2020 Oct 8.
Authors
Suphannika Phutthachalee 1 2 , Kathrin Mählmann 1 , Suvaluk Seesupa 2 , Christoph Lischer 1
Affiliations
1 Equine Clinic, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany.
2 Faculty of Veterinary Medicine, Khon Kaen University, Thailand.

Abstract

Background: Compensatory lameness is common in horses and evaluation can be challenging.

Objectives: To investigate patterns of compensatory movements in clinical cases with fore- or hindlimb lameness before and after diagnostic analgesia.

Study design: Retrospective clinical study.

Methods: Multiple limb lameness of 367 horses was characterised by type (push-off, impact or mixed), limb (fore- or hindlimb in predominant lameness) and side (ipsi- or contralateral in concurrent lameness) using a body mounted inertial sensor (BMIS). Diagnostic analgesia was performed until the percentage improvement of the vector sum in forelimb lameness and the mean difference of the maximum or minimum pelvic height (PDmax or PDmin) in hindlimb lameness were ≥50%. Linear mixed model and post-estimation of effects were performed by contrast command with multiple comparisons adjusted by Bonferroni method. Correlation of pre- and post-analgesia of all head and pelvis asymmetry parameters were tested with Spearman’s rank correlation.

Results: Improvement in vector sum per mm after diagnostic analgesia in forelimb impact lameness positively correlated with decrease of PDmax in contralateral mixed lameness (0.187 mm, r = 0.58, p<0.05). Improvement in PDmin per mm after diagnostic analgesia in hindlimb mixed and PDmax in hindlimb push-off lameness decreased vector sum in ipsilateral forelimb impact lameness by 0.570 and 0.696 mm, respectively (p<0.05) with no positive correlation.

Main limitations: A variety of cases with inhomogeneous distribution of lameness patterns was investigated retrospectively, therefore, it is impossible to distinguish between true multiple limb lameness and compensatory lameness in this clinical material.

Conclusions: Various asymmetry patterns of concurrent lameness were seen in horses with naturally occurring primary forelimb impact lameness with contralateral compensatory hindlimb lameness with a mixed component being the most common. In horses with hindlimb lameness, compensatory movements were seen in ipsilateral forelimbs, mostly as an ipsilateral impact lameness during straight line trot.

Keywords: contralateral; horse; ipsilateral; objective examination; type of lameness.