NCT07439705

The Effect of Heel Skin Mechanoreceptors on Plantar Flexor Contraction Force

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 29 (actual)
• Sponsor: Istanbul Physical Medicine Rehabilitation Training and Research Hospital · Other Government
• Sex: Male
• Age: 20 Years – 40 Years
• Healthy volunteers: Accepted

Summary

Previous studies have shown that stimulation of heel skin mechanoreceptors facilitates the soleus H-reflex, whereas stimulation of metatarsal region mechanoreceptors inhibits the soleus H-reflex. From this perspective, plantar cutaneous receptors may play an important role in the regulation of activities such as walking and running, as well as in the control of spasticity in patients with upper motor neuron lesions. Investigating the effect of heel skin mechanoreceptors on plantar flexor muscle contraction force may provide valuable insight into the potential influence of these mechanoreceptors on locomotor activities and muscle tone, and may offer a foundation for future studies directly addressing these topics.

Detailed description

The aim of this study is to investigate the effect of heel skin mechanoreceptors on plantar flexor contraction force. The plantar flexor muscle strength of the participants was evaluated using a force sensor connected to a computer. For the isometric muscle strength measurement, the subjects were asked to perform maximal plantar flexion for 10 seconds. A 5-pulse stimulation package at 15% contraction level was delivered 10 times with a 4-6 second interval. The measurements were repeated 10 times with a 30-second interval. During the plantar flexion muscle strength measurement, the heel skin mechanoreceptors were stimulated at sensory threshold by a square wave electrical current with a pulse duration of 1 microsecond.

Conditions

• Heel Skin Mechanoreceptors
• Plantar Flexion Contraction Force

Interventions

Type	Name	Description
OTHER	Assesment of Plantar Flexion Muscle Strength During Heel Skin Mechanoreceptor Stimulation	For the measurement of isometric muscle strength, participants lying prone on an examination table were instructed to perform maximal plantar flexion for 10 seconds. To achieve a submaximal contraction corresponding to 15% of their maximal contraction force, they were asked to follow the 15% threshold reference line displayed on the force channel on the screen. During the measurement of plantar flexion muscle strength, the cutaneous mechanoreceptors of the heel were stimulated with a square-wave electrical current with a pulse duration of 1 microsecond, at an intensity three times the sensory threshold. Electrical stimulation was delivered via a constant-current stimulator (Digitimer DS7A, Hertfordshire, United Kingdom). At the 15% contraction level, a train of five stimuli was delivered 10 times at intervals of 4-6 seconds. Measurements were repeated 10 times with 30-second intervals between each set.

Timeline

• Start date: 2025-09-01
• Primary completion: 2026-01-23
• Completion: 2026-02-20
• First posted: 2026-02-27
• Last updated: 2026-02-27

Locations

1 site across 1 country: Turkey (Türkiye)