There are four main causes of lower leg pain in runners . This update offers guidance on how to manage each of them .
Therapy Update
Running pains
RUNNING is a popular pastime in Australia that is encouraged by many organisations as being beneficial for one ’ s health .
Like all pursuits in life , there is a risk – reward ratio . Injury to the lower limb is the biggest risk , with university athletes having injury rates between 25-65 % and soldiers similarly 20-50 %. 1
As health practitioners , we need to be aware of , and not miss , these common injuries .
Popliteal artery entrapment syndrome ( PAES ) This is a well-described syndrome that is probably an underdiagnosed cause of exertional leg pain .
There are two types of entrapment : anatomical and functional . Anatomical entrapment involves a clear anatomical lesion causing arterial occlusion , usually in the older population , and requires surgical intervention .
The more common functional syndrome occurs because of overcrowding of the popliteal fossa : the medial head of the gastrocnemius compresses the popliteal artery between it and the lateral condyle , plantaris or lateral head of gastrocnemius .
Patients present with exercise-induced calf pain , bilateral in around onethird of cases . Pulses are usually palpable and ankle
brachial index is normal .
Examination post-exercise may be more rewarding with decreased peripheral pulses and a popliteal bruit .
Investigation is usually by Doppler ultrasound , but is limited due to a high falsepositive rate . MRI angiography in association with provocative manoeuvres ( passive dorsiflexion or active plantar flexion of the ankle ) may provide extra information .
Management Conservative management involves reviewing training loads , massage and strengthening . Failure rates for conservative treatment are high .
Concerns regarding endothelial damage to the popliteal artery with prolonged entrapment means surgical intervention is often recommended . This usually involves releasing the entrapment of the popliteal artery by the medial head of the gastrocnemius and usually is successful in the short term . Long-term studies have not been performed .
Complications include infection and ongoing
SPORTS MEDICINE
There are four main causes of lower leg pain in runners . This update offers guidance on how to manage each of them .
DR SCOTT MASTERS
symptoms of entrapment .
While functional PAES responds poorly to conservative treatments , surgical management carries risk of complications and poor outcomes .
Botulinum toxin type A ( BTX-A ) is showing promise , with few side effects and a reasonable chance of a good outcome .
The treatment involves injecting 50 units of BTX-A into two sites under ultrasound guidance . Usually this involves a medial approach to the medial head of the gastrocnemius and lateral approach to the plantaris muscle .
Patients need to rest for the remainder of the day and must not be involved in any high-intensity training for the next four weeks . 2 Top-up injections may be needed every six months .
About 60 % of patients will obtain a substantial improvement in their symptoms , with complication rates being very low and mostly mild ( calf ache ).
BTX-A works by direct muscle paralysis and eventual atrophy . It is also possible that there may be some effect on relaxing popliteal artery smooth muscle . Cost may be an issue .
Chronic exertional compartment syndrome The exact cause of pain in compartment syndrome has not been conclusively elucidated and the original theory of ischaemia has not been substantiated . Further research is needed , but we do know that it is a relatively common cause of exerciseinduced leg pain .
The anterior and lateral compartments are commonly involved , as is the deep posterior compartment .
The cardinal symptom that differentiates this condition is the predictability pain onset at certain levels of exertion . It usually goes away quickly with rest , but as it progresses , it comes on with less activity .
Examination should aim to rule out medial tibial stress syndrome or stress fractures ; search for tenderness and check leg pulses for signs of arterial insufficiency . There may be muscle herniation through the fascia .
Diagnosis is confirmed through intracompartmental pressure-testing . The patient ’ s pain must be predictable with exercise for this test to be contemplated . It is usually performed as a prelude to surgical intervention .
Management Management usually starts with a trial of conservative therapy . Biomechanical assessment of running style and load , manual therapies such as deep tissue massage , dry needling , prolotherapy and BTX-A injections have all been used with some success .
If conservative measures fail , which is not uncommon , surgery can be considered if compartment pressure testing is positive . Anterior and lateral compartment procedures can usually be performed with percutaneous endoscopically assisted releases and minimal incisions . Deep posterior compartment surgery may require fairly extensive release , but minimal surgery is usually attempted first to minimise morbidity .
Complications of surgery vary between 11 % and 16 %, and include superficial peroneal nerve damage , haematoma , DVT , infection , complex regional pain syndrome and wound dehiscence .
Recurrence rates may be as high as 40 % with surgery , the deep posterior compartment having the poorer prognosis . Anterior and lateral compartments have a 80-90 % success rate . 3
Medial tibial stress syndrome ( MTSS ) For people who run , this is one of the most common injuries , with an incidence of 15-20 %. 4 A recent review of the literature revealed the primary risk factors were :
• increased BMI ;
• increased navicular drop ( measure of arch height and pronation );
• increased plantar flexion range of motion ; and
• increased hip external rotation . 1 Interestingly , quadriceps angle and ankle dorsiflexion were clearly not risk factors for MTSS .
The old periostitis pathophysiology causation theory has gone and current evidence supports a bony overload injury theory .
This suggests that microdamage during tibial loading , coupled with inadequate recovery and repair time , leads to local tibia osteopaenia . Palpation of the junction of the soft tissue and posteromedial aspect of the tibia reproduces the pain patients feel while exercising . Focal tenderness should alert the practitioner to the possibility of a stress fracture . cont ’ d next page
www . australiandoctor . com . au 18 August 2017 | Australian Doctor | 27