Sprains and Strains



  • Sprains are complete or partial ligamentous injuries either within the body of the ligament or at the site of attachment to bone.
    • Classified as grade 1, 2, or 3 (AMA Ligament Injury Classification)
      • Grade 1: stretch injury without ligamentous laxity
      • Grade 2: partial tear with increased ligamentous laxity but firm end point on exam
      • Grade 3: complete tear with increased ligamentous laxity and no firm end point on exam
    • Usually secondary to trauma (e.g., falls, twisting injuries, motor vehicle accidents)
    • Physical exam is the key to accurate diagnosis.
  • Strains are partial or complete disruptions of the muscle, muscle–tendon junction, or tendon.
    • Classified as
      • First degree: minimal damage to muscle, tendon, or musculotendinous unit
      • Second degree: partial tear to the muscle, tendon, or musculotendinous unit
      • Third degree: complete disruption of the muscle, tendon, or musculotendinous unit
    • Often associated with overuse injuries

Geriatric Considerations
More likely to see associated bony injuries due to decreased joint flexibility and increased prevalence of osteoporosis and osteopenia

Pediatric Considerations

  • Sprains and strains account for 24% of pediatric injuries.
  • 3 million pediatric sports injuries occur annually.
  • Consider physeal/apophyseal injuries in the skeletally immature patient.


~80% of all U.S. athletes experience a sprain or strain at some point.


  • Ankle sprains are among the most common injuries in primary care, accounting for ~30% of sports medicine clinic visits. Most ankle sprains are due to inversion injuries (lateral sprains) involving the anterior talofibular ligament; account for 650,000 annual ER visits in the United States
  • Predominant age
    • Sprains: any age in physically active patient
    • Strains: usually 15 to 40 years of age
  • Predominant sex: male > female for most; female > male for sprain of anterior cruciate ligament (ACL)

Etiology and Pathophysiology

  • Trauma, falls, motor vehicle accidents
  • Excessive exercise; poor conditioning
  • Improper footwear
  • Inadequate warm-up and stretching before activity
  • Prior sprain or strain

Risk Factors

  • Prior history of sprain or strain is the greatest risk factor for future sprain/strain.
  • Change in or improper footwear, protective gear, or environment (e.g., surface)
  • Sudden increase in training schedule or volume
  • Tobacco use, medication adverse effects

General Prevention

  • Appropriate warm-up and cool-down exercises
  • Use proper equipment and footwear.
  • Balance training programs improve proprioception and reduce the risk of ankle sprains.
  • Semirigid orthoses may prevent ankle sprains during high-risk sports, especially in athletes with history of sprain.
  • Proprioception and strength training decrease injury risk; stretching does not

Commonly Associated Conditions

  • Effusions, ecchymosis, hemarthrosis
  • Stress, avulsion, and/or other fractures
  • Syndesmotic injuries
  • Contusions
  • Dislocations/subluxations

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