The ankle

CHAPTER 11 The ankle

Approximately 14% of all sports injuries are sprains to the ankle, representing one ankle injury each season for every 17 participants. In high risk sports, such as jumping and running, this percentage is even higher, at 25% of all lost-time injuries (Reid, 1992). Ankle sprain has been shown to be 2.4 times more common in the dominant leg, and to have a high (73.5%) prevalence of recurrence (Yeung et al., 1994).

The joint mechanics of the ankle and foot have been described in Chapter 7. The ankle joint is the articulation between the trochlear surface of the talus and the distal ends of the tibia and fibula. The fibula may support 15–20% of the body weight (Lambert, 1971), with the fibula moving downwards and laterally during the stance phase of running to deepen the ankle mortice and enhance stability. This fibular motion creates tension in the interosseous membrane and tibiofibular ligament to provide some shock attenuation. Loss of this mechanism through tibiofibular disruption greatly affects the ankle joint, with a 1–2 mm lateral shift of the fibula increasing joint forces by as much as 40% (Reid, 1992).

The ankle is subjected to considerable compression forces during sport (Fig. 11.1). Compression forces as high as five times body weight have been calculated during walking and up to 13 times body weight during running (Burdett, 1982).

Collateral ligaments

The joint is strengthened by a variety of ligaments, the collaterals being the most important from the point of view of injury. Both medial and lateral collateral ligaments travel from the malleoli, and have bands attaching to the calcaneus and talus.

The medial (deltoid) ligament (Fig. 11.2A) is triangular in shape. Its deep portion may be divided into anterior and posterior tibiotalar bands. The more superficial part is split into tibionavicular and tibiocalcaneal portions, which attach in turn to the spring ligament. The lateral ligament (Fig. 11.2B) is composed of three separate components, and is somewhat weaker than its medial counterpart. The anterior talofibular (ATF) ligament is a flat band 2–5 mm thick and 10–12 mm long which travels from the anterior tip of the lateral malleolus to the neck of the talus, and may be considered the primary stabilizer of the ankle joint (Palastanga, Field and Soames, 1989). The posterior talofibular (PTF) ligament travels almost horizontally from the fossa on the bottom of the lateral malleolus to the posterior surface of the talus. Lying between the ATF and PTF ligaments is the calcaneofibular ligament, arising from the front of the lateral malleolus to pass down and back to attach onto the lateral surface of the calcaneum. The role of the collateral ligaments in maintaining talocrural stability is summarized in Table 11.1.

Table 11.1 Role of the collateral ligaments in ankle stability

Movement Controlled by
Abduction of talus Tibiocalcaneal and tibionavicular bands
Adduction of talus Calcaneofibular ligament
Plantarflexion ATF ligament and anterior tibiotalar band
Dorsiflexion Posterior tibiotalar band and PTF ligament
External rotation of talus Anterior tibiotalar and tibionavicular bands
Internal rotation of talus As above with ATF ligament

Adapted from Palastanga, Field and Soames (1989).


The most common injury to the ankle is damage to the ATF ligament with or without involvement of the peroneus brevis. The subtaloid and mid-tarsal joints may be involved, but will be dealt with separately for clarity. The typical history of ankle injury is one of inversion, sometimes coupled with plantarflexion. The athlete ‘goes over’ on the ankle, usually on an uneven surface. One of three grades of ligament injury may occur.


There is usually an egg-shaped swelling in front of, and around, the lateral malleolus. When viewed from behind, the definition of the Achilles tendon is a good indicator of severity of injury (Reid, 1992). With more severe injuries (grade III) the definition of the Achilles tendon is lost due to excessive bleeding into the joint (Fig. 11.3).

Objective measurement of swelling is made using the figure-of-eight measure, a valid and reliable measure (Mawdsley, Hoy and Eerwin, 2000; Rohner-Spengler, Mannion and Babst, 2007). For this test the end of a tape measure is placed on the anterolateral aspect of the ankle midway between the tibialis anterior tendon and the lateral malleolus. The tape is passed medially over the dorsum of the foot to the tuberosity of navicular and then beneath the plantar aspect proximal to the tubercle of the 5th metatarsal. The tape passes medially once more to rest distal to the medial malleous and is pulled across the Achilles back to the starting point.

Manual evaluation

The lateral malleolus should be gently palpated to assess if bone pain is present; if it is, an x-ray may be required (see below). If palpation reveals tenderness below, rather than over, the lateral malleolus and the athlete is able to bear weight, there is a 97% probability of soft tissue injury alone (Vargish and Clarke, 1983). Any fracture that is missed by this type of close palpation is likely to be an avulsion or non-displaced hairline type that will respond favourably to management as a sprain (Garrick and Webb, 1990).

Stress tests to the ankle are useful to assess the degree of instability in the subacute phase, and to give a differential diagnosis. Acute injuries may be exacerbated by full range motion with overpressure. The capsule of the ankle joint itself is assessed by passive dorsiflexion and plantarflexion only, the capsular pattern presenting as a greater limitation of plantarflexion. However, as the ankle ligaments span the subtaloid and mid-tarsal joints, inversion/eversion and adduction/abduction are also included in ankle joint examination.

The ATF ligament is placed on maximum stretch by passive inversion, plantarflexion, and adduction. The heel is held with the cupped hand and the subtaloid joint inverted. The opposite hand grasps the forefoot from above and swings it into plantarflexion and adduction. In addition, anterior glide of the talus on the tibia should be assessed with the foot in a neutral position. The heel is again held in the cupped hand, but this time the palm of the opposite hand is over the anterior aspect of the lower tibia. The calcaneus and talus are pulled forward as the tibia is pushed back. Movements are compared with that of the uninjured side for range and quality.

The calcaneocuboid ligament is stressed by combined supination/adduction and the calcaneofibular ligament by inversion in a neutral position. The medial collateral ligament is stressed by combined plantarflexion/eversion/abduction (anterior fibres) or eversion alone (middle fibres). Resisted eversion will not be painful unless the peronei are affected (see below).

Ligamentous laxity may be assessed using the anterior draw test when acute inflammation has subsided. The patient’s foot is placed in slight (10−15°) plantarflexion and the heel is gripped with the therapist’s cupped hand, while the other hand stabilizes the lower tibia and fibula. The heel is drawn forwards against an opposite force pressing the tibia backwards and the amount of anterior movement is noted if the talus moves out of the ankle mortice. The test determines the integrity of both the anterior talofibular ligament and the calcaneofibular ligament and has been shown to be valid when compared to surgical observation (van Dijk et al., 1996).

Following severe ankle sprain or fracture, a bony link may form between the tibia and fibula (tibiofibular synostosis). Typically, pain occurs after an injury, and increases during vigorous activity, mimicking stress fracture. Pain is most severe during the push-off action of running and jumping, and dorsiflexion is often limited to 90°, mimicking impingement pain (see below). The synostosis is revealed by x-ray and removed surgically (Flandry and Sanders, 1987).

Fractures associated with ankle injuries

Several fractures may occur at the time of injury, and can go unnoticed unless a thorough examination is carried out. Often these fractures only become apparent during rehabilitation when swelling begins to subside. It falls on the astute therapist to question why rehabilitation is not progressing normally and to refer for further investigation, which may include x ray, MRI or CT scan.

Management of an ankle sprain

Immediate management consists of the PRICE protocol, with electrotherapy modalities as appropriate. Intermittent pneumatic compression (IPC) used in conjunction with cooling is effective. In the subacute phase, massage, especially finger kneading around the malleolus, is of value in preventing the development of pitting oedema. Transverse frictions may be used to encourage the development of a mobile scar, and may be used as a prelude to manipulation for scar tissue rupture in a chronic injury. Grade II and III injuries present with marked swelling and are protected non-weight bearing (severe injury) or preferably partial weight bearing with a compression bandage. Where minimal swelling indicates a grade I injury, an eversion strapping may be applied to protect the ligament from inversion stresses and to shorten it. A felt wedge is used beneath the heel to evert the subtaloid joint, and a U-shaped pad is placed over the submalleolar depressions to prevent pockets of oedema forming and to apply even compression when the ankle is strapped. Adhesive strapping is applied after skin preparation or underwrap, initially to lock the subtaloid joint and then to passively evert the foot. The athlete can then walk partial weight bearing in a well-supporting shoe.

Early mobility is essential to increase ligament strength and restore function. For grade I and II injuries, early mobilization has been shown to be more effective than immobilization. In a group of 82 patients with these grades of injury, 87% who were immobilized with a plastercast for 10 days still had pain after 3 weeks. This compared to 57% of those who received early mobilization in the form of an elastic strap for 2 days followed by a functional brace for 8 days (Eiff, Smith and Smith, 1994). Even grade III injuries (rupture) respond better to conservative treatment than surgery. Studies have shown 87% good and excellent results with conservative management compared to 60% for surgery of grade III injuries. In addition at 6 weeks post injury the surgical group had limited range of motion not seen in the conservative group (Kaikkonen, Kannus and Jarninen, 1996).

Non-weight bearing ankle exercise is instigated within the pain-free range, and fitness is maintained by general exercise. Strapping is replaced by a tubular elastic bandage as pain subsides.

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Sep 4, 2016 | Posted by in SPORT MEDICINE | Comments Off on The ankle

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