Muscle Injury

Muscle injury and PRP

The PRP has been used extensively by our clinic’s doctors for the treatment of various illnesses such as the knee pain, shoulder pain and smaller joint pain, lower back pain, and for the aesthetic indications.

The muscle injury happens very frequently. The most common injury includes the “strains” or “pulls” and tear. The muscle injury affects a large population of athletes every day and every year. The muscle is attached to the bone at the both ends through the tendons. Therefore a great amount of force is exerted through the tendon during a burst of forceful activity such as the push-up of the first step of a sprint. During the bursting activities such as sprinting and smashing moment of the tennis game which require sudden change of direction of movement, the force applied across the musculo-tendon unit can be very explosive and immense.

The commonest injury occur during the non-aligned or also called eccentric loading of the muscle. This is to say, the muscle is contracting while it is elongating. The muscle that span across two joints are most susceptible to injury. Such muscle includes for example the hamstrings, the calf, and the quadriceps. The hip adductor muscle, which is the internal rotators is also quite commonly affected.



lateral epicondyle injury

Tennis elbow affect ligament insertion of the lateral elbow.

Some common factors that increase the athletes to injury are:

  • Older person
  • Any history of previous muscle injury
  • Less flexibility
  • Lack of muscle strength
  • Muscle fatigue

Muscle anatomy and function

All the muscle has a outer covering which allow it to move smoothly over one another. The muscle is made up of bundles of muscle fibers called fascicles. The fascicles is made up of myofibrils. The myofibrils is composed of microscopic sarcomeres. The sarcomeres are responsible for muscle contraction. Inside the sarcomeres are protein myosin and actin. The myosin pull against the thinner actin.  As the myosin pulls the sarcomere shorten, called contraction. Conversely, when the sarcomeres lengthen back to the initial position, the muscle lengthen.

The muscle injury starts to happen when the force it produces is so great. It is so great that the tissue start to tear apart. The location of this injury may occur:

  • within the muscle tissue itself or
  • at the point where the tendon attaches to the bone
  • at the point where the muscle joint the tendon, this being the most common injury as it is the weakest point along the whole length of the muscle.

The 3-stage healing process is:

  • During the first stage of muscle injury, inflammation and swelling set in.
  • During the proliferation stage, the muscle heal by regenerating muscle fibers from the stem cell nearby.
  • During the remodeling stage, significant amount of scaring tissue form. The muscle cannot fully regenerate, and this is thought to cause subsequent injury.

Diagnosis of muscle injury:

  • Based on history taking
  • Physical examination
  • Pain in the area of injury, worst during contraction
  • Sudden pain or feeling of being stabbed
  • Physical examination:
    • Swelling
    • Bruise
    • Defect when muscle is completely torn
    • Loss some strength and range of motion



Severity of muscle injury

Grade 1

Grade 2 Grade 3
Mild damage to individual fibers, < 5% fibers More muscle fibers damaged

Muscle not ruptured

Complete rupture

Palpable deficit

Minimal loss of strength and motion Significant loss of strength and motion Loss of motion and strength

Take surgery to repair, reattaches

Take 2-3 weeks to improve Take 2-3 months before complete return to athletics 3 months
X ray or CT scan can see if bone fragment detaches MRI can see deficit, ruptured structures, haematoma
Rx: RICE Rest, ice, compression, elevation) , NSAID (eg ibuprofen), progressive functional physical therapy RICE, NSAID, progressive functional physical therapy Surgery to reattaches
PRP may stimulate muscle healing, regeneration, less scar formation PRP may stimulate muscle healing, regeneration, less scar formation PRP may stimulate muscle healing, regeneration, less scar formation

Losartan (anti-hypertensive) is thought to reduce scaring.