Fig. 4 Flowchart showing the approach to LGMD. Most LGMD patients have greater affliction of the posterior rather than the anterior thigh compartment muscles. On the other hand, patients with dystrophinopathy and sarcoglycanopathy often have significant affliction of the quadriceps muscle. Dystrophinopathy often presents with early and marked changes in the gastrocnemii muscles, while patients with sarcoglycanopathy show no affliction of these muscles. Patients with dysferlinopathy most often show posterior thigh and posterior lower leg involvement with sparing of the sartorius, gracilis and biceps femoris. However, muscle affection can be variable, but clinically calf atrophy and absence of scapular winging are commonly present. Calpain-3 and FKRP patients present with predominant posterior thigh and posterior lower leg involvement. Calpain-3 patients usually show marked involvement of the soleus and medial gastrocnemius muscles. Furthermore, calf atrophy and scapular winging are usually observed. Conversely, FKRP patients have a more diffuse involvement of the posterior lower leg muscles, while the tibial anterior muscle is often spared or even hypertrophied