Facts behind Duchenne Gait
Duchenne muscular dystrophy (DMD) is the most common childhood muscular dystrophy caused by DMD gene mutation. The prevalence of the disease is 1 in every 3500 male live births. The progressive character of the disease is due to muscle wasting and its replacement by connective tissue. These changes lead to weakness, which will first affect the proximal muscle groups and the distal ones on a later stage, all of those compromising the child's posture and gait. It is very important that the physiotherapist keep an eye on the dynamic quantitative assessment of gait in patients with Duchenne Muscular Dystrophy as this would help in evaluating the progression of the disease and to adapt any appropriate therapy.
Duchenne Gait Pattern
Many studies are showing evidence of proximal weakness affecting the muscle groups first and then followed by distal weakness. As this is true for both upper and lower limb muscles we are going to focus on the lower limbs only and the characterisation of the Duchenne Gait. The first evident compensations are due to gluteus maximus weakness and tightness in the hip flexors. The consequence of this is development of lumbar lordosis, an excessive anterior pelvic tilt and a 'double bump' sagittal pelvic tilt. Muscle wasting in the quadriceps is affecting the knee movement in loading response, when patients trying to avoid flexion of the knee. Furthermore, the knee hyperextension later in stance might be due to an attempt to keep the body stable while compensating for the weak quadriceps. D'Angelo et al., demonstrated this in their study by showing absence of extensor knee movement in patients with DMD.
Looking at the distal parts of the lower limb, it has been found that there is an excessive foot plantarflexion during swing phase and this was due to compensatory movement in the flexors and abductors of the hip, in order to aid floor clearance. However, velocity and cadence in this population group is similar to those in healthy subjects but stride length is known to be reduced and step width increased. It is expected the gait pattern to get more severely affected once the children start developing ankle tightness and contractures of the hips.
Outcome Measures used in the assessment of Duchenne Gait
Manual Muscle Testing (MMT) can be used to determine the power of muscle groups in the lower limb. It is quick and inexpensive way to follow up on muscle strength.
Hand Held Myometry/Dynamometry is a similar method to the MMT with better reliability characteristics. It requires the use of device which placed against body parts measures the exact power of the muscles in Kg or Newtons.
Gait Analysis should be considered as gold standard in the assessment of gait in patients with DMD and similar neuromuscular conditions. The gait analysis will provide objective and quantitative information about gait pattern.
The six-minute-walking test (6MWT) is another objective outcome measure which can be applied in the assessment of patients with DMD. It has been validated for children with neuromusclar disorders and it is also used to predict the progression of the disease.
Gower sign is usually an early predictor of presence of neuromuscular disorder and can be used to detect changes in gait and posture.
Other disorders and dysfunctions that can present with Duchenne gait
The Duchenne gait in LCP, Becker and other similar conditions is characterized by:
- A trunk lean toward the affected stance limb.
- The pelvis is either level or elevated on the swinging limb side, during the single stance phace.
- A reduced hip abductor moment, producing a hip-unloading effect.
- D'Angelo, M. G., et al. (2009). "Gait pattern in Duchenne muscular dystrophy." Gait Posture 29(1): 36-41.
- Liang, W. C., et al. (2018). "The natural history of the patients with Duchenne muscular dystrophy in Taiwan: A medical center experience." Pediatr Neonatol 59(2): 176-183.
- Hsu JD, Furumasu J. Gait and posture changes in the Duchenne muscular dystrophy child. Clin Orthop Relat Res 1993;288(March):122–5.
- Stuberg, W. A. and W. K. Metcalf (1988). "Reliability of quantitative muscle testing in healthy children and in children with Duchenne muscular dystrophy using a hand-held dynamometer." Phys Ther 68(6): 977-982.
- Hamuro, L., et al. (2017). "Developing a Natural History Progression Model for Duchenne Muscular Dystrophy Using the Six-Minute Walk Test." CPT Pharmacometrics Syst Pharmacol 6(9): 596-603.
- Ambroise Holland. Duchenne looppatroon. Available from: http://www.youtube.com/watch?v=qbKcjeqdNvk[last accessed 25/05/13]
- Bettina Westhoff, Andrea Petermann, Mark A. Hirsch, Reinhart Willers, Rudiger Krauspe. Computerized gait analysis in Legg Calve Perthes disease - Analysis of the frontal plane. Gait & Posture October 2006; 24 (2):196-202
- Andrews, J. G. and R. A. Wahl (2018). "Duchenne and Becker muscular dystrophy in adolescents: current perspectives." Adolesc Health Med Ther 9: 53-63.
- Maricelli, J. W., et al. (2016). "Trendelenburg-Like Gait, Instability and Altered Step Patterns in a Mouse Model for Limb Girdle Muscular Dystrophy 2i." PLoS One 11(9): e0161984.