ISSUE 75 : Mar/Apr - 1989 - Australian Defence Force Journal

24 DEFENCE FORCE JOURNAL No. 75 March/April 89Muscular and Soft Tissue Conditions inthe Lower LegThe musculature of the lower leg is enclosedin four tight, intrinsic compartments of connectivetissue which are anchored to the tibia andfibula. In front, between the tibia and fibula,there is the interior compartment which containsthe tibialis anterior muscle, the toe extensorsand the blood vessels and nerves whichsupply the front of the lower leg and foot. Atthe back, the lower leg is divided into two compartments,one deep and one superficial. Thedeep one, which is located between the tibia andthe fibula and behind the tight connective tissueband (interossius membrane) that connects thetwo, contains the long toe flexers (flexordigitorum longus and flexer hallucis longus)and the tibialis posterior muscle. Nerves andblood vessels pass to the back of the lower legand sole of the foot through this deep compartment.The posterior superficial muscle compartmentat the back contains the broad, deepcalf muscle (the solens) and the superficial calfmuscle (the gastrocnemeus). On the lateralaspect of the leg, around the fibula, is a lateralcompartment which encloses the long and shortmuscles that arise from that bone (the peroneuslongus and brevis).Chronic Compartment SyndromesChronic compartment syndromes can occuras a result of the increase in muscle bulk followingprolonged intensive training. The increasein bulk causes the muscle to grow larger than isallowed for by the surrounding fascia sincethese tight membranes are not particularlyelastic. When the muscles are at rest there is noproblem, but during muscular work thousandsof smali blood vessels dilate, in order to increasethe blood flow and thus increase the bulkof the muscles too.Pressure is increased (which can cause pain)if a muscle in the lower leg is then required towork for any length of time and the blood flowis obstructed, causing a relative lack of oxygen.This changes the cell environment by the formationof lactic acid and fluid begins to lea'r;from the capillaries. Swelling (oedema; occurswithin the muscle and this further increases thepressure (and pain) on the muscle compartment,impairing blood flow even more. Thisvicious circle continues unless exercise ceases.Muscular contraction within the compartmentscan also exert traction on the periosteum,causing it to become inflammed (periostitis).Compartment syndromes can give symptomsat the front, at the back and on each side of thelower leg.Symptoms and Diagnosis(a) Anterior (front) compartment syndrome(acute)- A characteristic symptom is acute painwhich gradually increases until it becomesimpossible to continue running.- Weakness can occur when the foot is bentupwards.- A sensation of numbness extending downthe foot may be felt.- Local swelling and tenderness can be presentover the tibialis anterior muscle.- Pain can be triggered when the foot ortoes are passively bent downwards (plantarflexion).Treatment:The Recruit/Patient- Rest actively;- Cool the injured area.The Therapist- Apply ice compression and elevation.- Slow active non-weight bearing footmovements in the second 24-hours.- Gentle massage from ankle upwards tomobilise venus blood, lymphatics andoedema.- Pulsed ultra sound in the actue phase.- Rest.The Doctor- Prescribe diuretics.- Prescribe anti-inflammatory medication.- Check effectiveness of treatment bymeasuring the pressure in the musclecompartment.- In extreme cases, perform surgery(facialotomy).Symptoms and Diagnosis(b) Anterior Compartment Syndrome(chronic)- Pain which increases under load andwhich finally makes continued musclework impossible.