Introduction to strain injury

Definition

• A strain is an acute or chronic soft tissue injury to a muscle, tendon, or both.¹ 
• Tendons are tissues which attach muscles to bones. 
• When a similar kind of injury occurs to the ligament, it is called a sprain. 
• Ligaments are the tissues that connect one bone to another bone.
• When our body moves, the muscle stretches within its normal limits. Strain usually occurs when the muscle is overstretched beyond its ability. 

It is noticed that an injury may occur when there is an abrupt increase in 

• duration
• intensity
• frequency of activity

Types of strain injuries

Strain injury can be acute or chronic depending on the onset of the injury, whether sudden or prolonged. 

Acute strain

This happens due to sudden physical trauma resulting from forceful movements or overstretching of the muscles while doing certain exertional activities. For example, weight lifting or stretching muscles while jumping or sprinting. 

Chronic strain

This happens due to repetitive actions of certain muscles or overuse of a muscle for prolonged duration. For example, people who perform the same task daily like a sportsperson, can experience chronic strain. 

The strain injury can also be classified as:

• Grade 1 - Stretching and injury to the muscle fibres, but there is minimal structural damage
• Grade 2 - More extensive damage with more muscle fibres involved, however, the muscle is not completely ruptured
• Grade 3 - Complete rupture of a muscle or tendon² 

Common areas affected by strain injuries

• Lower back: Strain in the lower back is one of the most frequent injuries, especially among those who lift heavy objects or have poor posture
• Hamstrings: The muscles at the back of the thigh are commonly strained during activities that involve running, jumping, or sudden stops
• Neck and shoulder muscles: These areas are often affected by strain due to poor posture, especially in people who sit for long periods, such as office workers
• Forearms: Repetitive tasks, such as typing or sports like tennis, can lead to forearm strains. This is most commonly seen in individuals who repetitively perform motion through their hands and arms

Symptoms of strain injury

Signs and symptoms of strain injury can differ from person to person and it also depends on the severity of the injury. Some common symptoms are: 

• Pain
• Tenderness 
• Swelling 
• Bruising 
• Stiffness 
• Muscle weakness 
• Muscle spasms
• Numbness and tingling 

Pain and tenderness

The most common and first symptom of any injury is pain. It is the same for muscle strain. The affected area becomes painful. The patient will experience a pain which may or may not resolve on its own depending on the severity of the injury.

Swelling and bruising

Strained muscles or tendons can become swollen. Swelling can be accompanied by redness and warmth. In more severe cases, bruising may appear as blood vessels are damaged. 

Limited range of motion or stiffness

Strain injuries can limit the movement of the affected area. The pain and swelling will make it difficult to move that particular area. For example, it becomes difficult to walk when the leg muscle is strained.

Muscle weakness or spasms

Some strains can result in muscle weakness, where the muscle cannot perform its normal function. Muscle spasms, or involuntary contractions of the muscle, are also a common symptom. Muscle spasms are nothing but painful tightening of the muscles. 

Causes of strain injuries

• Overexertion: Many times we don't realise that a certain activity can cause severe exertion on the muscle. Activities that push muscles beyond their limits, such as lifting heavy objects or engaging in intense exercise without proper preparation, can lead to strain injuries
• Poor posture or body mechanics: A good Posture is very important for one’s muscle health. Incorrect posture while sitting, standing, or moving can cause more tension on muscles which can possibly lead to strain. For example, slouching while sitting can cause a neck or back strain
• Lack of proper warm-up before physical activities: Not warming up properly before engaging in physical activity can increase the likelihood of a strain injury. Warm-ups prepare the body and muscles for better movements and activities by improving blood flow and flexibility
• Repetitive motions: Performing the same movements repeatedly without rest can cause strain injuries. This is common in sports like tennis, in activities like typing, where the same muscle groups are used continuously

Diagnosis of strain injuries

Physical examination

Diagnosing a strain injury usually begins with a physical examination by a healthcare professional. During the physical exam, the doctor will check:

• range of motion
• check for tenderness
• evaluate the severity of the injury. 

Imaging tests

For severe cases, imaging tests may be required such as

• X-rays
• MRI scans

may be ordered to rule out other conditions or detect any severe damage to muscles or tendons.

Treatment options

First aid for sprain 

1. Stop the activity.
2. Rest the injured area.
3. Put ice packs on the affected area.
4. Compress or use a bandage on the injured area. 
5. Elevate the injured area above heart height whenever possible. 
6. Avoid heat and excess movements like running.
7. If symptoms persist or get worse in the first 24 hours, you need to see a doctor for further medical investigation.

Most muscle strains will heal on their own over a certain period. Some treatment options include:

RICE method²

• Rest
• Ice
• Compression 
• Elevation 

Physical therapy

In cases where the strain is more severe, a physical therapist may be recommended. Although resting the affected muscle is recommended, one must start mobilization gradually. Physical therapy involves exercises to strengthen and stretch the affected muscles, aiding in the recovery and preventing future injuries.

Medications

Over-the-counter pain relievers, such as NSAIDs (nonsteroidal anti-inflammatory drugs), which commonly include paracetamol and ibuprofen, can help reduce pain and inflammation.

Surgery

Very rarely, surgery may be required in case of a severely torn muscle or tendon. This will help restore normal muscle/tendon functions.

Other treatments include

• Bracing and external support 
• Manual techniques such as mobilisation and massage
• Electrotherapy³

Prevention of strain injuries

• Warm-up and stretching: Before engaging in physical activities, it is essential to warm up to increase blood flow and flexibility. Stretching can help loosen tight muscles and reduce the risk of strain
• Maintain Proper Posture: Whether sitting, standing, or performing tasks, maintaining correct posture helps minimize unnecessary stress on muscles. For example, using ergonomic furniture or adjusting the height of the workstation can help prevent neck and back strain
• Strengthening exercises: Regular exercises that target key muscle groups can help improve strength and endurance, reducing the likelihood of strain injuries
• Take breaks: When performing repetitive tasks, taking regular breaks helps prevent overuse of specific muscles. For example, if working on a desk job, one can take breaks and stand and stretch the body to relieve strain

When to see a doctor

• Severe pain or inability to move the affected muscle
• If there is a popping sound, which could be from the bone, at the time of injury
• Symptoms that don’t improve after a few days of home care
• Visible deformity or muscle rupture
• When one has an open wound
• When there is a fever

Summary

• Strain injuries are common but at the same time, they can be prevented
• By understanding the causes, types, and symptoms of strain injuries, individuals can take steps to avoid them and seek early treatment when necessary
• Simple measures like
  • warming up before physical activity
  • maintaining good posture
  • avoiding repetitive motions without rest.
• If a strain does occur, early treatment through methods like 
  • RICE approach
  • Physical therapy 

can speed up recovery and reduce the risk of chronic issues.