Myopathic gait
When the weakness is bilateral, there is an exaggerated pelvic swing with each step as the hip droops on the side of the swing leg that results in a “waddling” gait. The exaggerated pelvic swing resembles the stride of a runway model and is also sometimes referred to as a “sexy” gait. In extreme forms, this gait pattern has a bizarre appearance, especially in FSH dystrophy. The patient walks with a pronounced waddle, shoulders thrown back and pelvis thrust forward. This gait pattern is particularly common in facioscapulohumeral muscular dystrophy.
The video shows a young boy with a waddling gait due to pelvic girdle weakness.(3) Note also the lumbar hyperlordosis with the shoulders thrust backwards and the abdomen protuberant. This posture places the center of gravity behind the hips so the patient doesn't fall forward because of weak back and hip extensors.
References
1. Campbell WW. DeJong's the neurologic examination, 7th ed. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins, 2013.
2. Campbell WW. Clinical signs in neurology: a compendium. Philadelphia: Wolters Kluwer Health, 2016.
3. Video used by permission of Paul D. Larsen, M.D., University of Nebraska Medical Center and Suzanne S. Stensaas, Ph.D., University of Utah School of Medicine. Additional materials were drawn from resources provided by Alejandro Stern, Stern Foundation, Buenos Aires, Argentina; Kathleen Digre, M.D., University of Utah; and Daniel Jacobson, M.D., Marshfield Clinic, Wisconsin. The movies are licensed under a Creative Commons Attribution-NonCommerical-ShareAlike 2.5 License. Available at http://library.med.utah.edu/neurologicexam/html/gait_abnormal.html#13.