Muscle

MUSCLES
By Robert H. Sheinberg, D.P.M., D.A.B.F.A.S., F.A.C.F.A.S.

Muscles connect bones to tendons and move body parts when they contract. Injuries may be caused by direct trauma (contusion), overuse (myositis) or by overstressing the fibers causing them to tear. Occasionally bone may develop an injured muscle (myositis ossificans) causing prolonged pain and firm mass in the muscle. Treatment for muscle injuries includes immediate identification of the injured area and a thorough understanding of the cause of injury.

TYPES:

1. MUSCLE TEARS – Gastrocnemius – The gastrocnemius makes up a large portion of the calf muscle. The muscle below it called the soleus completes the large muscle belly in the back of the lower leg. The muscle connects the upper leg bone just behind the knee to the heel bone at the bottom of the foot. 

CAUSES:

  1. Overstretching the muscle beyond its elastic limits.
  2. Foot is moved up excessively when the knee locks during an activity.
  3. Usually associated with poor calf flexibility.
  4. Age causes loss of elasticity of muscle fibers.
  5. More common in men over the age of 35.
  6. Occurs after the muscle has warmed up and then cooled down for a short period of time. When the muscle is utilized actively again following the cool down phase tears are more common. (Example, second half of a flag football game, second or third set in a tennis match after resting between sets, second half of a basketball game after prolonged sitting during halftime.

SIGNS AND SYMPTOMS:

  1. Immediate feeling of a pop in the calf muscle. 
  2. May be confused with an Achilles tendon rupture.
  3. Immediate inability to weightbear on the foot. 
  4. Immediate pain and swelling.
  5. Swelling and discoloration extend down to the ankle and heel area.
  6. Difficulty weightbearing is usually present for at least 10-14 days.
  7. Underlying fracture of the bone must be ruled.

TREATMENT:

  1. Identify the extent of injury (partial versus complete tear).
  2. Ice to minimize the bleeding and swelling in the area, 20 minutes on, 40 minutes off as often as possible for the first 2-3 days.
  3. Anti-inflammatory medication may benefit in reducing the amount of inflammation. It has been shown to have beneficial effects in soft tissue injuries. 
  4. Compression with an ace bandage or a leg sleeve.
  5. Utilization of crutches for 7-10 days.
  6. Physical therapy is usually done after the first few days. Ultrasound, electrical stimulation may help to diminish the amount of swelling and limit the muscle damage. Treatment is then focused on exercising light off weightbearing range of motion exercises to allow contraction of the calf muscle. Over a period of time strengthening consists of both concentric (muscle shortening) and eccentric (muscle lengthening) exercises to promote full strength. 
  7. Slow return to sneakers or shoes with a heel lift after 2-3 weeks.

PROGNOSIS:
Prognosis for these injuries is excellent. They never need to be corrected surgically, even in a collegiate or professional athlete. Once the muscle tears, scar tissue usually develops between that region causing some thickening to the area that was torn. Recovery of muscle strength is usually present if the muscle has been mobilized shortly after the injury. A slight deformity also develops in the calf muscle when comparing it to the unaffected side. Full return to all sports activities should be allowed between 3 and 6 months depending on the degree of injury to the area. 

2. CONTUSIONS

CONDITION:
Contusions are bruises to the muscle usually caused by direct trauma. Trauma to the area causes the muscle to bleed, causing diffuse swelling, tenderness and discoloration over the affected area. If bleeding is excessive a hematoma (a collection of blood) may develop. Overlying redness and severe tenderness may be present. Difficulty ambulating due to stress on the muscle is usually seen. 

TREATMENT:

  1. Immediate application of ice and compression with an ace bandage are needed to lessen the bleeding and swelling in the affected area. 
  2. Most hematomas, following injuries to the muscle that are mild will absorb spontaneously over a period of 6-8 weeks. On rare occasions the bump present, which is a collection of blood that is organized into a firm clot, may persist for a long period of time. 
  3. Immobilization in a surgical boot with or without crutches may be necessary depending on the muscle affected and the symptoms. Most of the pain associated with the injury resolves over a one-week period of time. However, localized tenderness to touch will be present for many weeks. If a significant amount of redness and swelling develop in that area surgical evacuation of the hematoma may be needed to prevent further damage and to hasten the recovery process. During the procedure the large clot of blood that is present is removed through a small incision. The area is irrigated with saline. The incision is then closed. Antibiotics are usually necessary for a short period of time to either treat or prevent infection to the area. 

PROGNOSIS:Prognosis is excellent in almost all cases. Occasionally bone may develop within the muscle which may affect the long-term prognosis.

COMPLICATIONS:
Compartment Syndrome – The muscles in the leg are contained within small compartments. These compartments are surrounded by tight fascial structures that allow the muscles to expand during exercise and activity. Deep muscle bleeding occurs within the compartment. These tight fascial bands may not be able to expand and excess pressure develops within the compartment due to the bleeding. Usually signs and symptoms of a compartment syndrome include severe pain, numbness in the affected part or on the top or bottom of the foot. Extreme pain with attempts at passively stretching the muscle are also seen. Immediate attention to this problem is critical. Surgery to decompress the compartment and prevent nerve damage and allow a complete return to function.

3.MUSCLE STRAINS:
CONDITION: An injury to the muscle that has occurred most commonly following an athletic activity. The muscle has stretched to its elastic limit but has not torn. 

CAUSE:
Strains are more common when a person has done an activity without proper warming up. The warm up should include light exercises simulating the activity and muscle stretching. Muscle strains are usually caused by poor muscle flexibility. During loading of the muscle tendon unit powerful eccentric contraction (muscle lengthening contraction) can cause a strain to the muscle due to the increased tension generated by the muscle during this type of contraction. Usually less common during the concentric contraction (shortening of the muscle). Excessive stress to a muscle in a person or athlete doing an exercise or activity that they are unaccustomed to (i.e. strain of the lower back caused by excessive lifting, strain of the calf, excessively jumping when unaccustomed to it). 

SIGNS AND SYMPTOMS:
Soreness to the muscle usually develops within 24 hours of the activity. Depending on the severity of the condition a partial loss of function and strength are usually seen in the affected muscle group. There is a slight loss of muscle strength. Tightness to the affected muscle is felt. Difficulty walking may accompany it. Rarely is there any swelling or discoloration associated with these injuries.

TREATMENT:
Treatment is usually aimed at resting the muscle. Ice to the affected area (20 minutes on, 40 minutes off) for the first 48 hours may provide benefit. This will lessen the inflammation to the muscle region. The application of the heat 3 or more days later is beneficial before an activity to warm up the muscle. The muscle should then be lightly stretched to improve its flexibility. If there is pain associated with using the body part, rest is necessary until full range of motion is felt. This is followed by stretching the muscle to resume the muscle tendon length and strengthening the muscle to prevent recurrence. It is importance to focus on concentric and eccentric muscle contractions. 

PROGNOSIS:
Prognosis is excellent if the muscle has healed completely. Incomplete healing of a muscle followed by concentric or eccentric activity may predispose the muscle to a complete muscle tear and a more serious problem. 

4. MYOSITIS OSSIFICANS– Severe blunt trauma causing an intramuscular hematoma may result in delayed ossification. Severe muscle injuries, especially in the quadriceps may be accompanied by bone that grows within the muscle during the healing process. Following muscle injuries the body is supposed to lay down new muscle cells and scar tissue to heal the area. In myositis ossificans abnormal bone growth develops within the muscle tissue causing a firm mass within the muscle itself. This can become painful affecting an athlete’s ability to return to sports. It may limit the muscle’s overall flexibility and predispose it to further problems. This can include further strains to the muscle. The muscle will generally be weaker than the unaffected side. The condition is rarely without symptoms. X-rays are necessary to make the diagnosis. Bone tumors must be ruled out. The appearance of the bone on x-rays may help to distinguish a tumor from myositis ossificans. MRIs may be necessary for further evaluation. When myositis ossificans develops aggressive rehabilitation protocol is necessary to improve flexibility to the muscle. Concentric and eccentric exercises are also necessary to maximize the muscle strength, hopefully preventing further injury. Surgery is indicated when the bone mass continues to be painful and interferes with joint movement and muscular activity. The mass may rarely impinge upon the nerves creating nerve compression and the symptoms associated with it. Surgery must be delayed for 6-24 months during which time the mass has matured. 

X-RAYS:
Round mass with distinct outer margin. Center is usually radiolucent.

PROGNOSIS:
Over time the volume of heterotopic bone usually diminishes. Recovery of normal muscle function in the presence of myositis ossificans is usually delayed. Indomethacin (strong nonsteroidal anti-inflammatory) may be of benefit in diminishing the volume of bone and lessening the pain associated with the condition.

MYOSITIS is an inflammation of the muscle usually caused by overuse. Shin splints are a form of this where the muscle starts pulling away from the bone causing inflammation to develop at the muscle bone junction. 

CAUSES:
Inflammation of muscle is usually caused by overuse. Especially common in people who are performing in activity they are not accustomed to. Also common in athletes in the early part of a training season. It is also common in athletes in the early part of a training season.

SYMPTOMS:  Symptoms include pain with activity, tenderness and occasionally swelling over the injury site. Symptoms worsen over time then start to preclude sports. 

TREATMENT:

  1. Rest, ice and compression of the muscle. 
  2. The decrease in training intensity or stopping the activity if the pain is moderate to severe.
  3. Shoe gear changes may be necessary. 
  4. Physical therapy may be needed which would include stretching and strengthening exercises to prevent recurrence. 

Surgery is rarely necessary unless an underlying cause cannot be treated conservatively.


MRI of gastrocnemius muscle where the area indicated by the red arrows is a tear in the muscle tissue which shows as bright white within the normal dark muscle tissue.

Contusion of the leg with swelling and ecchymosis as a result of a tear in the muscle belly of the calf.