Plantar Flexor Function in Adults with and without Prader-Willi Syndrome

Area of Science:

• Neuromuscular Physiology
• Muscle Biology
• Movement Science

Background:

• Prader-Willi Syndrome (PWS) is a genetic disorder associated with congenital obesity, hypotonia, and physical/cognitive disabilities.
• The specific causes of muscle dysfunction and their impact on mobility in PWS are not well understood.

Purpose of the Study:

• To compare plantar flexor muscle function in adults with and without PWS.
• To investigate the relationship between plantar flexor function and gait speed in adults with PWS.

Main Methods:

• 10 adults with PWS, 10 obese controls, and 10 non-obese controls were assessed.
• Plantar flexor function was evaluated using isokinetic dynamometry, Hoffman reflex, ultrasound imaging, and gait analysis.
• Statistical analyses included MANOVA for group comparisons and Pearson correlation for associations.

Main Results:

• Adults with PWS demonstrated reduced peak torque, rate of torque development, and Hoffman reflex compared to controls.
• Muscle morphology in PWS showed lower cross-sectional area and higher echo intensity.
• Plantar flexor strength and muscle characteristics correlated with faster gait speeds in the PWS group.

Conclusions:

• Adults with PWS have impaired plantar flexor function, stemming from reduced neuromuscular capacity and altered muscle structure.
• These functional deficits in plantar flexors contribute to slower gait speeds in individuals with PWS.