Acute Lateral Ankle Sprain Impairs Function and Strength Without Altering Muscle or Tendon Stiffness: A Controlled...

Area of Science:

• Biomechanics
• Musculoskeletal injuries
• Rehabilitation science

Background:

• Acute lateral ankle sprain (LAS) is a common injury leading to persistent functional limitations.
• Understanding the mechanical changes in calf muscles and Achilles tendon (AT) post-LAS is crucial for elucidating functional deficits.

Purpose of the Study:

• To investigate the impact of acute LAS on calf muscle and AT mechanical properties.
• To assess changes in ankle function, pain, edema, and strength following acute LAS.

Main Methods:

• Controlled observational study involving 14 participants with acute LAS and 14 healthy controls.
• Evaluations conducted at baseline and 6 weeks using shear wave elastography (SWE) for muscle/tendon stiffness, functional outcome scores, pain and edema measures, and isometric dynamometry for strength.
• Comparison between LAS group and controls, and within-group changes over time.

Main Results:

• No significant differences in calf muscle or AT stiffness were observed between groups or over time, though AT stiffness showed a general increase.
• The LAS group presented with significantly reduced ankle function, increased pain, and greater edema at baseline, with improvements noted at follow-up.
• Plantar flexion strength was lower in the LAS group, and overall strength increased in both groups over the 6-week period, with ankle function remaining impaired in the LAS group at follow-up.

Conclusions:

• Acute lateral ankle sprain (LAS) leads to reduced ankle function, pain, and edema.
• No significant changes in calf muscle or Achilles tendon stiffness were detected within 6 weeks post-injury.
• Despite functional improvements and strength gains, persistent deficits in ankle function are evident 6 weeks after LAS.