HISTORY Pain from the ankle is mostly felt around the ankle, or into the mid-foot. Injury or pain from the more superficial structures tends to be located by tenderness of those structures. Local tenderness, swelling and pain are the symptoms. Passively stretching the ligament confirms the diagnosis. Deeper structures such as the true ankle usually presents with pain around the ankle with tenderness over the anterior aspect of the joint. Ankle pain is rarely referred away from the ankle/ foot.

It’s important to know the method

of injury in order to ensure correct diagnosis, this includes the activity pursued and the force exerted on the ankle.

Inversion injury is the most common

acute injury. The anterior talo-fibular ligament (ATFL) (Figure 8) on the lateral aspect of the ankle is the mostly commonly injured ligament in the body. Simple inversion injury i.e. ‘going over on the ankle’ causes the injury when the stretch receptors don’t activate the spinal reflex in time. Under normal circumstances the reflex causes the peroneii to contract and resist the inversion. Injury varies in intensity from simple ATFL injury, followed by injury to the peroneii, then a traumatic arthralgia to the sub-talar joint (signified by tenderness just superior to the sustenaculum tali), followed by fracture without true ankle joint disruption, to either the lateral malleolus tip or the base of the fifth metatarsal, both avulsion fractures, and lastly Potts fractures Grades I to III involving disruption of the mortice and tenon of the true ankle joint.

©2010 Primal Pictures

DEFINITIONS

n Fore-foot - consists of the metatarsals and phalanges n Mid-foot - consists of the tarsal bones i.e. navicular, cuboid, and three cuneiforms (see figure 1) n Rear-foot - consists of the talus and calcaneum n Supination - is a 3-D (triplanar) combination movement at the subtalar joint of eversion, abduction and dorsi-flexion – the foot moves down and towards the centre of the body n Pronation - is a 3-D (triplanar) combination movement of inversion, adduction and plantar flexion (i.e. opposite of supination) – the foot moves up and away from the centre of the body

Cracks and snapping noises

associated with the injury often don’t signify fracture, more often ligament damage. Application of the Ottawa ankle rules should be the doctor’s guide to whether to x-ray or not (2). Locking and giving way is rare in

the ankle. A loose body is most likely to be a boney fragment - either think osteochondritis dissecans of the tibia - (x-ray may be useful) or fragments from an osteophyte. True locking comes on suddenly and goes off quickly, often with the ankle positioned/ moved in the same way. It is painful! The patient will often have self-learnt a movement/trick to unlock it by wiggling the foot. Giving way often causes pain that’s sufficient for the patient to stumble and fall. There may be no acute injury.

Figure 8: Key ligaments of the ankle

Anterior talofibular ligament (ATFL)

Overuse usually involves excessive pronation (hereafter called pronation) involving increased range of movement (ROM). This causes excess stress on other structures. This may cause symptoms or even new conditions that may be located further up the kinetic chain, far from the ankle. Though not universally accepted, pronation can cause bunion formation, sesamoiditis, callus formation on the foot, heel bumps, Achilles tendonitis, anterior knee pain, trochanteric bursitis, sacroiliac pain and low back pain. The axis of the sub talar joint either directs the injury forward into the foot or up the leg. Overuse injuries are caused

by repetitive movements of an increased nature, often with underlying biomechanical problems. Learning the aetiology and pathology, then recognising them in the patient, is the key to our diagnosis and treatment. Enquire about sports, extra activities, new footwear (including flip-flops during summer), new sporting goals e.g. Half

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or full marathons, charity runs, running to lose weight; as this may point to overuse problems.

Pronation Correct movements of the lower limb are based on the saggital plane. Excess frontal or transverse plane compensations can cause biomechanical or overuse injuries. Pronation is a combination movement of inversion, adduction and plantar flexion and occurs in all three planes saggital, frontal plane and coronal planes. Over-pronation is caused by mechanical deviations in the foot away from the 90o

angle formed by the leg

and foot. Common problems that cause over-pronation are rear foot inversion/ eversion, forefoot inversion/eversion, and equinuus deformity.

See video 6 in the interactive extras section for a demonstration of excessive pronation in the right foot during running.

The foot pronates to adapt to the surface of the ground changing the foot from the adaptive mode to propulsive mode. The degree of pronation is the angle of rotation the foot has to move to reach the ground to allow first ray (first metatarsal/great toe) to come into contact with the ground and allow propulsion. Excess pronation occurs secondary to structural deviations (see above). Usually when young, the extra flexibility of the tissues allows this without symptoms. Either stiffening tissues or acute injury e.g. gout in the first MTP joint causes stiffness which causes the pronation stress to be transferred elsewhere. The ‘elsewhere’ depends on the axis of the subtalar joint. For example as the foot pronates to reach the floor it causes medial rotation of the tibia which is then transmitted up the lower limb (see video 5 in Interactive extras).

EXAMINATION

My personal examination technique involves Look, Move and Feel. The order is more physio-like to encourage the full range of movement (FROM) possible before one causes pain by palpation. Firstly the patient uncovers the whole of the lower leg.

Look n As the ankle is required for standing, observe both ankles weight bearing

sportEX medicine 2010;46(Oct):11-16