Effect of walking speed on gait parameters in individuals with myotonic dystrophy type 1.

BACKGROUND

Myotonic dystrophy type 1 is a prevalent inherited muscular dystrophy in adults, affecting distal muscles. This leads to significant gait deviations and reduced walking speed, impacting overall well-being and increasing fall risk. This study aimed to assess how walking speed affects gait kinematics in individuals with myotonic dystrophy type 1.

METHODS

Eighteen individuals with myotonic dystrophy type 1 (4 women, age: 41.0 [35.5; 47.8] years, mass: 76.8 [67.1; 94.6] kg, height: 166.0 [156.7; 173.3] cm) participated in this study. Each participant walked barefoot along a 13-m walkway at comfortable and fast speeds. Spatiotemporal parameters and joint kinematics were assessed.

FINDINGS: The step length (p < 0.001), cycle speed (p < 0.001), and cadence (p < 0.001) increased significantly, leading to a higher walking speed. Moreover, the vertical excursion of the center of mass increased significantly (p = 0.015), while the mediolateral amplitude decreased (p = 0.001) at fast walking condition. In addition, significant kinematic changes included increased trunk tilt (p < 0.001), greater anterior pelvic tilt (p < 0.001), increased hip flexion at initial contact, and enhanced knee flexion during both stance and swing phases. Ankle dorsiflexion showed a trend towards increase during stance phase (p = 0.055) at fast walking condition.

INTERPRETATION: Fast walking speed in individuals with myotonic dystrophy type 1 lead to significant gait changes. These changes reflect mechanisms to manage muscle weakness. The present study revealed significant changes in spatiotemporal parameters related to walking speed and highlighted kinematic changes in trunk, pelvis and lower limb joints. These findings enhance our understanding of gait mechanisms in this population.