REHABILITATION ANKLE INJURY

End-range joint-positioning activities should be undertaken repeatedly to stimulate the higher brain centres and thus to create a learning response. The ability to move from conscious to unconscious motor programming is vital for the athlete to perform at the highest level without the consequence of re-injuring the ankle complex. Initially the athlete will concentrate on the proprioception task in order to facilitate and maximise sensory input. With progress, the activities incorporate cognitive aspects, which aid in converting conscious joint stabilisation and control to unconscious motor programming (26,27). In order to enhance motor function at

the brain stem, balance and postural sway activities should be employed. A progression of static (in the early stages) through to dynamic (in the later stages) balance exercises should be undertaken with and without visual feedback. The use of uneven surfaces is classically a good way to enhance the late stages of this part of proprioceptive stimuli and should always incorporate activities from the athlete’s sport, such as swinging a racquet or kicking a ball. The ability to introduce and duplicate speed with balance, relating to the individual’s sport, is vital in order to achieve this higher unconscious learning response. To stimulate the spinal level of motor

control, activities that create sudden movement are needed to promote unconscious reflex joint stabilisation. Plyometric and jump- and catch-based activities encourage joint muscle activity and address the neuromuscular activity at the spinal level. These exercises should be incorporated towards the end of the rehabilitation programme in order to protect the healing tissue. Muscle stimulation is also encouraged in the early stages, as long as joint reaction and thus joint oedema are minimal. This is undertaken in non-weight- bearing exercises simply by asking the athlete to respond to stimulation via the therapist’s hands (perturbation) and asking the athlete to stop any sudden movement in any direction.

This stimulus is best applied without visual aid, but it is important to ensure that muscle activity around the ankle is minimal before the application of a directional force is applied. The athlete is asked to respond quickly to the movement applied by the therapist, by counteracting the movement with quick muscle activity. Peroneal reaction time is significantly shorter in stable compared with unstable ankles (28), and emphasis on the peroneal muscles is always of benefit within the rehabilitation programme – although the time and amplitude in which the peroneal muscles fire under static conditions may not reflect what occurs during an actual injury (22).

STRENGTH Eccentric

Isometric maximum

0 Velocity Figure 5. Force–velocity relationship for muscle www.sportEX.net Concentric

The capacity of muscles to produce force and afford stabilisation to a joint can be assessed by using static (isometric) or dynamic (isotonic or isokinetic) contractions. Figure 5 shows the relationship between concentric and eccentric muscle force and speed. It is vital when devising a strength programme to understand the progressions of load and how speed influences the different forms of muscle action. A gradual progression of concentric>isometric>eccentric is a normal flow when trying to progress load on a tissue. The ability to change the force by applying various speeds during isotonic muscle action can influence the load going through the injured tissue and surrounding joints. In the early stages the athlete needs strength adaptation, without re-injuring the damaged tissue, with increasing force being applied through high-speed eccentric or low-speed concentric muscle actions in the later stages.

Joints of the lower limb do not work in isolation. Consequently, dysfunction at one level has multiple effects throughout the kinetic chain (29), although the contribution of dynamic strength imbalances to chronic ankle instability is still controversial (20,30,31). Peroneal strength training has shown great benefit, both functionally and mechanically, to the rehabilitation of injured ankles (32,33). Bonnin was the first to realise that the frequency of ankle sprains depended on muscular control (34). With the ever-increasing use of eccentric muscle action within rehabilitation programmes, it is not surprising that eccentric peroneal strength is advocated. The use of this type of muscle training can be seen to have a decelerating effect on the mechanism of inversion ankle sprains (35,36). However, Lentell and colleagues tested concentric and isometric strength in the invertors/evertors of the ankle but did not find peroneal weakness in previously injured ankle groups (30). Bernier and colleagues assessed eccentric ankle inversion/eversion strength and found no difference between patients’ healthy and injured ankles (37). McKnight and Armstrong (38) looked at using concentric/eccentric strength measurements as criteria to returning an injured ankle back to play. They found no differences in testing injured compared with non-injured ankles and concluded that other factors should be used to determine the athlete’s return to play. Other studies have considered the relationship of agonist versus antagonist (39,40). Most of these studies have tended to evaluate the ratios on already injured ankles, and thus a pre-existing strength loss can have

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Force