How does rectus femoris fibrosis affect gait?

We report on a female patient with stiff-knee gait resulting from rectus femoris fibrosis, following multiple injections into the quadriceps musculature. Treatment planning and outcome were aided by instrumented three-dimensional gait analysis. One year after surgery, improvements were found in walking speed, step length, anterior pelvic tilt, knee flexion in swing, and ankle dorsiflexion in swing. Instrumented three-dimensional gait analysis was a useful tool for characterizing gait impairments and detecting changes after surgical intervention. Intramuscular injections into the rectus femoris muscle should be avoided to prevent stiff-knee gait and associated disability. Level of evidence: Level IV, case report. (C) 2014 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.