Muscle strain: symptoms, causes and prevention

Muscle Strain: symptoms, causes and prevention

Muscle strains are one of the most common injuries that occur, typically among the sporting population. A muscle strain occurs when the muscle fibres cannot cope with the demands placed on them resulting in tearing of the fibres. This can be a result of a powerful contraction or over-stretching of the muscle. Therefore, it is typical in non-contact sports with dynamic characteristics such as sprinting or jumping.


Muscle strains are often classified as Grade I, II & III based on the severity of the injury:

  • Grade I (mild) strain – small fibre ruptures, minor swelling, no loss of function and activity can usually continue.
  • Grade II (moderate) strain – mild fibre ruptures, increased swelling, reduced strength of the musculotendinous unit and usually unable to continue with activity.
  • Grade III (severe) strain – complete rupture, significant swelling and pain and loss of muscle function.


Symptoms of a muscle strain may include:

  • Swelling, bruising or redness around the site of injury
  • Pain and tenderness around the site of injury
  • Limited range of motion
  • Weakness of the muscle or tendon


Muscle strains commonly occur when:

  • Abnormal loads are being put through normal structures e.g. lifting something too heavy
  • Normal loads are being put through abnormal structures e.g. lifting an everyday object with poor back alignment or fatigued muscles
  • Abnormal loads through abnormal structures e.g. lifting a heavy object with poor back alignment or fatigued muscles
  • Overuse or repetitive stress that occurs over time


A good starting point for preventing muscle strains is ensuring you are conditioned for that sport. This can be achieved through your physiotherapist designing a training program that focuses on any strength, mobility and load management needs specific to your sport.

A biomechanical assessment should also be performed by your physiotherapist to determine if you are safe to play that sport. The physiotherapist will conduct a thorough screening to highlight and address any biomechanical abnormalities you may have to minimise the risk of injury.

If you have experienced a muscle strain or would like to learn more about injury prevention, our expert team of physiotherapists at Unique Physio will help guide you in the right direction.

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