The Effect of Heel Skin Mechanoreceptors on Plantar Flexor Contraction Force

NCT07439705 | Completed DMC

• 1 other identifier: 2025-58
• Study Type: interventional
• Target: 29
• Locations: 1 country
• Sites: 1

Brief 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.

Conditions

Heel Skin Mechanoreceptors; Plantar Flexion Contraction Force

Keywords

Skin mechanoreceptor; Ruffini corpuscle; Pacinian corpuscle; Contraction forcee

Outcome Measures

Primary Outcomes (3)

• Voluntary Contraction Force

  While the participants were lying prone on the examination table, plantar flexion muscle strength was assessed using a computer-connected force sensor (SPIKE 2.7). For detailed analysis of the participant data using the SPIKE 2.7 force sensor software, an IIR digital filtering process was first applied to the force channel. During this procedure, a low-pass filter was selected. The filter settings were configured with a cutoff value of 100 and an order of 2. As a result of this filtering process, the newly generated filtered memory channel was labeled "ForceLP." Subsequently, the waveform average of the ForceLP channel was calculated with the following settings: width 4 s, offset 2 s, and trigger set to 6 stimuli (event+). From these averaged traces peak contraction force was determined.

  Day 1 (During a single experimental session)

• Reflex Contraction Force

  While the participants were lying prone on the examination table, plantar flexion muscle strength was assessed using a computer-connected force sensor (SPIKE 2.7). For detailed analysis of the participant data using the SPIKE 2.7 force sensor software, an IIR digital filtering process was first applied to the force channel. During this procedure, a low-pass filter was selected. The filter settings were configured with a cutoff value of 100 and an order of 2. As a result of this filtering process, the newly generated filtered memory channel was labeled "ForceLP." Subsequently, the waveform average of the ForceLP channel was calculated with the following settings: width 4 s, offset 2 s, and trigger set to 6 stimuli (event+). From these averaged traces reflex contraction force was determined.

  Day 1 (During a single experimental session)

• Reflex Contraction Latency

  While the participants were lying prone on the examination table, plantar flexion muscle strength was assessed using a computer-connected force sensor (SPIKE 2.7). For detailed analysis of the participant data using the SPIKE 2.7 force sensor software, an IIR digital filtering process was first applied to the force channel. During this procedure, a low-pass filter was selected. The filter settings were configured with a cutoff value of 100 and an order of 2. As a result of this filtering process, the newly generated filtered memory channel was labeled "ForceLP." Subsequently, the waveform average of the ForceLP channel was calculated with the following settings: width 4 s, offset 2 s, and trigger set to 6 stimuli (event+). From these averaged traces reflex contraction latency was determined.

  Day 1 (During a single experimental session)

Study Arms (1)

Prone position

EXPERIMENTAL

Plantar flexor muscle strength is assessed in the supine position. For the measurement of isometric muscle strength, participants lay prone on an examination table and were instructed to perform maximal plantar flexion for 10 seconds. To achieve a submaximal contraction corresponding to 15% of their maximal voluntary contraction, participants were asked to follow a 15% threshold reference line displayed on the force channel monitor.

Other: Assesment of Plantar Flexion Muscle Strength During Heel Skin Mechanoreceptor Stimulation

Interventions

Assesment of Plantar Flexion Muscle Strength During Heel Skin Mechanoreceptor Stimulation OTHER

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.

Prone position

Eligibility Criteria

• Age: 20 Years - 40 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Being healthy
• Being between 20 and 40 years of age
• Being female or male
• Volunteering to participate

You may not qualify if:

• Having a history of orthopedic conditions-particularly in the lower extremity-or residual neuromusculoskeletal problems due to previously experienced illnesses

Sponsors & Collaborators

• Istanbul Physical Medicine Rehabilitation Training and Research Hospital: lead

Study Sites (1)

Istanbul Physical Medicine and Rehabilitation Training and Research Hospital

Istanbul, Istanbul, 34180, Turkey (Türkiye)

Location

Related Publications (5)

• Burke D, Dickson HG, Skuse NF. Task-dependent changes in the responses to low-threshold cutaneous afferent volleys in the human lower limb. J Physiol. 1991 Jan;432:445-58. doi: 10.1113/jphysiol.1991.sp018393.

  PMID: 1886063 RESULT

• Aniss AM, Gandevia SC, Burke D. Reflex responses in active muscles elicited by stimulation of low-threshold afferents from the human foot. J Neurophysiol. 1992 May;67(5):1375-84. doi: 10.1152/jn.1992.67.5.1375.

  PMID: 1597720 RESULT

• Germano AM, Schlee G, Milani TL. Effect of cooling foot sole skin receptors on achilles tendon reflex. Muscle Nerve. 2016 Jun;53(6):965-71. doi: 10.1002/mus.24994. Epub 2016 Apr 26.

  PMID: 27113729 RESULT

• Nakajima T, Sakamoto M, Tazoe T, Endoh T, Komiyama T. Location specificity of plantar cutaneous reflexes involving lower limb muscles in humans. Exp Brain Res. 2006 Nov;175(3):514-25. doi: 10.1007/s00221-006-0568-6. Epub 2006 Jul 18.

  PMID: 16847613 RESULT

• Sayenko DG, Vette AH, Obata H, Alekhina MI, Akai M, Nakazawa K. Differential effects of plantar cutaneous afferent excitation on soleus stretch and H-reflex. Muscle Nerve. 2009 Jun;39(6):761-9. doi: 10.1002/mus.21254.

  PMID: 19260052 RESULT

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator Physiatrist

Model Details: For the measurement of isometric muscle strength, participants lay prone on an examination table and were instructed to perform maximal plantar flexion for 10 seconds. To achieve a submaximal contraction corresponding to 15% of their maximal voluntary contraction, participants were asked to follow a 15% threshold reference line displayed on the force channel monitor.During the measurement of plantar flexion muscle force, heel skin mechanoreceptors were stimulated using 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.

Study Record Dates

• First Submitted: February 23, 2026
• First Posted: February 27, 2026
• Study Start: September 1, 2025
• Primary Completion: January 23, 2026
• Study Completion: February 20, 2026
• Last Updated: February 27, 2026

Record last verified: 2026-02

Locations

TU (1)