RSSFunctional Ankle Instability
July 20, 2009 by David Fitzgerald
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Filed under Physiotherapy Blog
Persistent Post-Traumatic Ankle Pain
The prevalence of ongoing ankle symptoms post sprain is widely recognised internationally. This is most widely recognised as persistent functional ankle instability the mechanisms of which remain elusive, with a spectrum of suspected pathologies involving…
Mechanical disruption of the stabilising ligaments
Proprioceptive impairment
Persistent strength deficits
Peripheral nerve pathology
Altered biomechanics,
Mal-adaptive muscle recruitment throughout the kinetic chain.
It is important for the clinician to establish whether the actual ‘giving way’ associated with functional instability is in fact a pain inhibitory mechanism or directly associated with biomechanical incompetence.
In order to determine the likelihood of a pain inhibitory mechanism the clinician must search for drivers of pain, which are compatible with inducing the nociceptive stimulus to induce the reflex inhibitory response. In this respect detailed examination of the ankle joint not only with regard to provocation of symptoms but detection of altered mechanics is of critical importance.
A common clinical observation is the presence of post-traumatic capsular restriction producing limitation of ankle dorsiflexion or plantarflexion. This is particular relevant because the capsular restriction alters the accessory Talar movement within the ankle mortis and therefore can block the normal accessory motion. This is particularly so in the presence of a dorsiflexion block in which the patient describes anterior or intra-articular discomfort.
Functionally this presents as…
Reduced squat depth
Impaired descending of stairs
Weight transference in terminal stance
Pain at the limits of plantarflexion is more commonly reported on the posterior aspect of the joint but may also be associated with sensations of passive restriction on the anterior capsule. In the presence of one or both of these features of capsular restriction, there is a definite role for manual therapy to restore capsular elasticity and appropriate accessory Talar movements. A failure to do so often results in persistent intra-articular impingement, which can often mimic joint surface defect pathology, or the more frequently recognised osseous impingement syndromes. On this basis the astute clinician will clear these clinical signs in an effort to resolve symptoms prior to pursuing further radiological or explorative investigations in cases of chronic ankle instability.
So the take home message to differentiate ankle impingement secondary to capsular restriction from articular surface pathology is to…
Restore physiological range of dorsiflexion and plantarflexion
Restore accessory Talar motion
Differentiate potential articular surface pathology by applying Talar distraction at end range ankle motion.
Quantify capsular end-feel at limit of range
Rise to the clinical challenge
David
