Characteristics 

Chronic ankle instability is defined by enduring feelings of apprehension within the ankle, recurrent instances of the ankle giving way, and repeated ankle sprains persisting for a minimum of six months post-initial sprain. Patients with chronic ankle instability typically have a medical history characterized by repeated ankle sprains and significant inversion injuries, often impacting the anterior talofibular ligament (ATFL), the calcaneofibular ligament (CFL), and/or the posterior talofibular ligament (PTFL). 

Symptoms indicative of chronic ankle instability encompass lateral ankle pain and ongoing swelling. As a result of these injuries, they tend to take specific precautions to avoid weight-bearing activities, strenuous exercises, and walking on uneven or rough surfaces.

Regarding impairments associated with chronic ankle instability, notable factors include heightened ligamentous laxity and proprioceptive deficits. These impairments contribute to limitations in various activities such as walking and jumping. Furthermore, in terms of participation, individuals with chronic ankle instability may find themselves ceasing participation in sports, withdrawing from or reducing occupational involvement, experiencing decreased exercise levels, and even altering the type of sport they engage in 

Causes 

Chronic ankle instability is primarily attributed to two key factors: diminished proprioceptive abilities stemming from the loss of mechanoreceptors and weakened invertor and evertor muscle strength.

Following a lateral ankle sprain (LAS), not only are ligaments structurally compromised, but the mechanoreceptors within joint capsules, ligaments, and tendons surrounding the ankle complex also sustain damage. These mechanoreceptors play a vital role in relaying feedback about joint pressure and tension, aiding in the perception of joint movement and position. This sensory input is integrated with visual and vestibular cues, forming a complex control system responsible for regulating posture and coordination. When injury disrupts afferent input, it can lead to alterations in corrective muscular contractions, potentially contributing to functional impairments and chronic instability post-injury. 

Proprioception

Proprioception is defined as the sensory information relayed to the central nervous system by mechanoreceptors located in various tissues including joint capsules, ligaments, muscles, tendons, and skin. Trauma to tissues containing these mechanoreceptors can result in partial differentiation, leading to proprioceptive deficits that contribute to chronic ankle instability. Studies have shown postural control deficits during quiet standing following acute LAS and in individuals with chronic ankle instability. 

Muscle Weakness

Additionally, researchers have identified weakness in the peroneal muscles as a contributing factor to chronic ankle instability. Deficits in evertor strength reduce the muscles’ ability to resist inversion and return the foot to a neutral position, potentially increasing susceptibility to inversion sprains. Notably, eccentric evertor weakness has been observed in patients with chronic ankle instability. 

Management 

In contrast to acute ankle sprains, chronic ankle instability often necessitates surgical intervention. However, before resorting to surgery, non-surgical approaches are strongly advocated for patients with chronic ankle instability. Research indicates that repetitive ankle joint injuries lead to neuro-sensory, proprioceptive, and mechanical impairments. Therefore, exercises aimed at enhancing proprioception, balance, and functional capacity are typically incorporated into treatment protocols following an ankle joint injury, alongside muscle strengthening exercises.

Neuromuscular training

Neuromuscular training involves the unconscious activation of dynamic restraints, which prepare and respond to joint motion and loads, thereby maintaining and restoring functional joint stability. The primary objectives of neuromuscular training are twofold: first, to enhance lower limb postural control, and second, to rehabilitate active stability through targeted training methods. 

Balance training 

Balance training can affect multiple joints and produce overall improvements. It significantly improves functionality, instability, and dynamic balance outcomes in people with chronic ankle instability 

Mobilization 

Limited ankle dorsiflexion during jogging and walking presents a risk factor for recurrent sprains due to several factors. Firstly, insufficient dorsiflexion restricts the ankle joint’s ability to reach its closed-packed position during stance, compromising its stability. Secondly, individuals with limited dorsiflexion may have a tendency to lock the midfoot in supination, further compromising the ankle’s ability to adapt to uneven surfaces or sudden changes in terrain. Lastly, the lateral movement of the center of gravity caused by limited dorsiflexion increases the vulnerability of the ankle joint to supination and subsequent sprains, as the joint lacks the necessary flexibility to absorb and adapt to these forces effectively. Hence, mobilization with movement intervention will definitely benefit patients with chronic ankle instability by increasing dorsiflexion range of motion.  

Taping 

Physiotherapists will apply taping in order to improve patients’ perceptions of stability and decrease mechanical laxity.  

Strengthening exercise 

Chronic ankle instability often leads to weakness in the muscles surrounding the ankle joint, including the peroneal muscles, which play a crucial role in stabilizing the ankle during movement. Strengthening exercises help to rebuild strength in these muscles, improving their ability to support and protect the ankle joint. 

Associated lesions

Chronic ankle instability is often associated with lesions that evolve from contributory factors. They do not necessarily occur with chronic ankle instability, and if any, not all these lesions occur together. 

Sinus tarsi syndrome is frequently observed in specific populations such as basketball and volleyball players, dancers, overweight individuals, as well as those with flatfoot and hyperpronation deformities. This condition manifests as pain and tenderness in the sinus tarsi, located on the lateral side of the hindfoot. It can develop after a single severe ankle sprain or as a result of repetitive ankle injuries (Al-Kenani & Al-Mohrej, 2016).

Osteochondral defects (OCD) are injuries that affect the talus bone. These injuries can manifest as the blistering of cartilage layers, the formation of cyst-like lesions within the bone, or even fractures involving both bone and cartilage layers. OCD can be caused by a single traumatic event or recurrent trauma over time. Symptoms of OCD typically include swelling, instability in the ankle joint, and persistent pain that extends over a prolonged period (Al-Kenani & Al-Mohrej, 2016). 

Peroneal tendinopathy is chronic inflammation of the peroneal tendon resulting in weakness of the active ankle stabilizers. This happens when a person performs a repetitive activity that stresses the tendon over a long period. In addition, poor and rapid training and poor shoe wear may cause peroneal tendinosis. People who have a hindfoot varus posture are more likely to experience peroneal tendinosis (Al-Kenani & Al-Mohrej, 2016).