Calf pain is a common presenting complaint and if not managed appropriately it can persist for months or recur and cause frustration for both patient and practitioner. Both acute and chronic calf pain often stem from injury to the calf muscle. The term 'calf muscle' refers to the gastrocnemius and soleus muscles. The more superficial muscle, the gastrocnemius has medial and lateral heads that arise from the femoral condyles, while the deeper soleus arises from the upper fibula and the medial tibial border. These muscles have a joint tendon, the Archilles, which inserts onto the calcaneus.
As a biarthrodial muscle extending over the knee and the ankle, the gastrocnemius is thought to be more susceptible to injury than a uniarthrodial muscle.
Clinical perspective
Injuries to the musculo tendinous complex are by far the most common causes of calf pain. Muscle strains occur most commonly in the medial head of the gastrocnemius or near the musculotendinous junction. A sudden burst of acceleration, such as stretching to play a ball in squash or tennis, precipitate injury. The calf region is also a common site of contusion caused through contact with playing equipment or another player. Muscle strains and contusions are acute injuries that present with typical histories that are usually easily distinguishable.
Some patients present with intermittent episodes of cramping pain in the calf that may be due to recurrent minor calf muscle strain, which is a result of inadequately rehabilitated scar tissue. However, the possibility of referred pain from the lumbar spine, neural or my facial structures should always be considered. The calf is the most common site in the body of muscle cramps. Cramps may occur at rest or during or after exercise taken in any environmental conditions- they are not specific to exercise or exercise in heat. They tend to occur in the more acclimatized and conditioned athlete and probably result from alterations in spinal neural reflex activity activated by fatigue in susceptible individuals. The calf is also a common site of the phenomenon known as delayed onset muscle soreness. This may occur after the first training session following a lay-off or when excessive eccentric muscle contractions are performed, for example, plyometrics. Lateral calf pain may be due to a direct blow, referred pain from the superior tibiofibularjoint, peroneal muscle strain or fibular stress fracture.
Bio mechanical factors may predispose to calf pain. Excessive subtalar pronation may overload the soleus and gastrocnemius muscles as they supinate and plantar flex the foot for propulsion. This can cause muscle tightness and soreness and may predispose to muscle strain or tendinopathy. Muscle overload can promote muscular hypertrophy, which can predispose to the development of a compartment syndrome.
Investigations
Although investigations are generally not required in an athlete with calf pain, ultrasound or MRI may occasionally be useful in evaluating an injury that is not following the normal healing pattern. These imaging modalities can differentiate between a muscle strain and a contusion if not clinically evident. If deep venous thrombosis is suspected, a Doppler scan may be required.
Claudicant-type calf pain
A common presentation to a sports physician is the patient who complains of a Claudicant- type calf pain with exercise. The differential diagnosis in this patient is a vascular cause (popliteral artery entrapment, atherosclerotic disease, and endofibrosis), neuromyo fiscal causes (referred pain or nerve entrapment) or compartment syndrome (deep posterior or superficial).
Vascular causes
Vascular causes of exercise-induced lower limb pain are uncommon and difficult to diagnose. The pain of vascular entrapment is difficult to differentiate from that caused by compartment syndrome and nerve entrapment, although there are subtle differences in the relationship of the pain to the bout of exercise. Post-exercise examination of the peripheral pulses and arterial bruits is vital and the diagnosis can be confirmed by Doppler ultrasound, ankle-brachial ratios and angiography. It may also be important to perform compartment pressure tests and nerve conduction studies to rule out coexisting conditions.
Popliteal artery entrapment
Popliteal artery entrapment syndrome is often not recognized and misdiagnosed as a compartment syndrome but can cause exercise-induced calf pain, “The syndrome was first described as a cause of exercise induced leg pain in 1879. There are two types of popliteal artery entrapment syndrome: anatomical and functional.
The classically described anatomical abnormality is a variation in the anatomical relationship between the popliteal arteries as it exits the popliteal fossa and the medial head of the gastrocnemius muscle. Five such variations have been described, the commonest being an abnormal medial head of the gastrocnemius muscle, the accessory part of which is observed to pass behind the popliteal artery. Other observed abnormalities include a tendinous slip arising from the medial head of the muscle, an abnormal plantar is muscle and multiple muscle abnormalities involving the lateral and medial heads of the gastrocnemius and the plantar is, rarer anatomical variations of popliteal artery entrapment syndrome include entrapment of the artery at the level of the adductor hiatus and an isolated entrapment of the anterior tibialartery as it passes through the interosseous membrane.
The term 'functional' popliteal artery entrapment syndrome was first described by Rignaultetal in 19857 and describes a situation where no anatomical abnormality is visible at surgical exploration. It is hypothesized that muscle contraction (active plantar flexion of the ankle) compresses the artery between muscle and the underlying bone. This may explain why the syndrome is commonly seen in healthy young athletes with hypertrophied gastrocnemius muscles.
The pain of popliteal artery entrapment syndrome is Claudicant pain felt in the calf or anterior aspect of the leg. The pain is brought on by exercise and the severity of the symptoms is related to the intensity of exercise. Cessation of exercise tends to bring about rapid relief from the pain. This compares with the classic pain pattern of compartment syndrome which is related to the volume of exercise and tends to settle over a period of around half an hour after exercise. If exercise is attempted on consecutive days, the pain from a compartment syndrome is often more severe on the second day. The pain from popliteal artery entrapment syndrome is unaffected by exercise on the previous day. The pain can be paradoxically more severe on walking than on running. This is believed to be due to the more prolonged contraction of the gastrocnemius muscle while walking.
Roughly 10% of patients with popliteal artery entrapment syndrome present with signs and symptoms of either acute or chronic limb ischemia with Paraesthesia, discoloration of the foot and toes, temperature change, rest pain and tissue necrosis.
Examination at rest can sometimes identify a popliteal artery bruit with forceful, active ankle plantar flexion or passive dorsi flexion, but examining the patient immediately post-exercise is important in making the diagnosis. Immediately post-exercise a popliteal artery bruit may be heard and the peripheral pulses will be either weak or absent.
Non-invasive investigations include post-exercise ankle- brachial pressures and Doppler ultrasound. The definitive diagnosis is made on angiography but it is important for the radiologist to image the arterial tree with the patient actively plantar flexing and actively and passively dorsi flexing the ankle. In our experience unfortunately, there appears to be a significantly high rate off positive tests using this method. Correlation between the investigation results and clinical suspicion is therefore vital.
Treatment
Treatment involves open surgical exploration of the popliteal fossa and division of the offending fiscal band. There is some suggestion that the presence of chronic entrapment of the popliteal artery can lead to endothelial damage, which may lead to accelerated atherosclerotic disease in later life. Early treatment is recommended to prevent the development of popliteal artery damage and the need for grafting.
Atherosclerotic vessel disease
Atherosclerotic vessel disease classically affects middle-aged sedentary patients. However, some athletes, particularly in the veteran or masters class, fall into the category of middle-aged or elderly and possess risk factors that predispose them to atherosclerosis. Pain may be felt in the thigh or the calf and is typically Claudicant. With progression of the disease, the intensity of exercise needed to produce symptoms decreases. At rest, the peripheral pulses may be difficult to palpate or absent. An arterial bruit may also be heard at rest. The presence of such bruits may be enhanced by examining the patient post-exercise. The gold standard diagnostic test is Doppler ultrasound although pre-and post-exercise ankle-brachial ratios can be used as a non -invasive screening test. A giography can confirm the diagnosis. Surgical treatments include angiographic balloon catheter dilatation or stentling, open end arterectomy or bypass surgery. Bypass surgery is the most commonly used surgical technique for atherosclerotic vessel disease and its success depends on the extent of the disease and on the viability of the smaller distal vessels.
Endofibrosis
Endofibrosis disease can cause exercise-related calf pain, although more commonly the pain is fell in the thigh. Typically the lesion occurs in the proximal external iliac artery-but may extend distally towards the origin of the femoral artery beneath the inguinal ligament. It is bilateral in 15% of cases. External iliac artery endofibrosis has been described in professional cyclists and causes exercise related thigh or calf pain that is related to the intensity of cycling. The pain is therefore most commonly felt while racing, climbing a hill or riding into a strong wind. The pain is typically relieved rapidly by a drop in the intensity of exercise. It is postulated that the cycling position may cause folding of the artery and result in micro-traumatic lesions, and psoas hypertrophy has also been postulated to be involved.
Examination at rest may reveal a positional bruit over the femoral artery with the hip held in flexion. The diagnosis is made clinically by examining the patient immediately post-exercise, detecting a bruit over the femoral artery and weak or absent distal pulses. Pre- and post-exercise ankle brachial ratios screen for the diagnosis, which is anatomically confirmed with angiography. Arterial ultrasound or echography can also be useful in visualizing the endofibrotic lesion.
Non -surgical techniques for the treatment of external iliac artery endofibrosis include angioplasty balloon catheter dilatation and stenting, which can be planned for and performed at the time of angiography. Surgical techniques include bypass surgery and open end arterectomy. Use of these techniques has made a return to top level cycling and triathlon possible in patients. However, long-term follow up of such patients has not been carried out.
The natural history of this pathology is not certain. However, Abrahametal suggest that it is non progressive once high level sport is ceased. They advise that an athlete who is reducing his/her sports level, and who is a symptomatic with activities of daily living and sub maximal, be managed conservatively but followed up regularly.
Physical Therapy is an important aspect of treatment in pain conditions. Physical Therapists use different techniques to give relief to the sufferers, physical therapy create strength, regain mobility, and help the people to come back to their normal condition. So treat your Calf Pain with Physical Therapy.
