This is a multicenter, simple blind, masking of outcomes assessors, parallel, randomised clinical trial in patient with muscle rupture and with hematoma production. The main hypothesis is that infiltration in the area of muscle injury in autologous platelet-rich plasma (PRP)improves muscle regeneration and repair by shortening the time to complete recovery.

The main objective is to evaluate the PRP for healing muscular lesions 'tennis leg' type or distal rectus femoral. The secondary objectives are: to evaluate the risk of lesion recurrence; to evaluate the quality of lesion recovery process and evaluate intervention's safety.

Experimental treatment will be the administration of PRP autologous (4-8 cc in a unique dose) by muscular infiltration en the empty space generated after the hematoma evacuation. Control treatment will be hematoma evacuation. Both treatment groups will use compressive bandage and they will recommend rest, extremity elevation, local ice and lately physiotherapy.

Size sample: 76 patients (38 in each group)

Inclusion Criteria:

• Adults over 18 years
• Lesion with haematoma at the Gastrocnemius muscle or the lower portion of the rectus femoral muscle
• Acceptance to participate at the clinical trial
• Not indicated the surgical treatment of the muscle injury

Exclusion criteria

• Patients who do not meet the inclusion criteria
• History of bleeding disorders
• Inability to follow-up the patient
• The use of corticosteroids, acetylsalicylic acid(Aspirin ®) and nonsteroidal antiinflammatory drugs during the study