Peripheral Magnetic Stimulation of Foot Muscles
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 30
- 试验地点
- 3
- 主要终点
- Change in medial longitudinal arch height
研究概览
简要总结
This study examines the effects of repetitive peripheral magnetic stimulation (rPMS) on foot invertor muscle strength, morphology, and the height of the medial longitudinal arch (MLA) in individuals with flat feet. The rPMS will be applied non-invasively to the extrinsic and intrinsic foot muscles three times per week for twelve weeks. The experimental group will receive rPMS targeting the invertor muscles of the foot, while the control group will not receive stimulation but will follow the same measurement schedule.
Assessments will be performed at baseline, after 6 weeks, and after 12 weeks of intervention. The primary outcome will be the change in the height of the MLA, evaluated using dynamic navicular drop assessment during gait. Secondary outcomes will include changes in the isometric inversion torque of the foot invertors and morphological adaptations of the tibialis posterior muscle assessed by ultrasound imaging.
This study seeks to determine whether rPMS can improve the height of the MLA, foot invertor muscle strength and structural stability in adults with flat feet. The findings may contribute to developing new, non-invasive therapeutic approaches for improving foot function and preventing musculoskeletal imbalances related to flat foot deformity.
详细描述
During movement, the role of the foot muscles is often overlooked. Through their strength and stabilizing function, foot muscles play an important role in maintaining balance, posture, and force transmission throughout the body. Proper activation of these muscles also helps preserve the stability of the medial longitudinal arch (MLA), thereby influencing the overall biomechanics of human movement.
The foot muscles are classified as extrinsic (originating outside the foot) and intrinsic (originating and inserting within the foot). Extrinsic muscles, primarily stabilize the ankle joint and control larger movements, whereas intrinsic muscles store and release elastic energy within the foot, contributing to arch support and movement efficiency.
A lowered height or collapsed arch of the foot, known as flat foot (pes planus), is characterized by arch flattening during weight-bearing and affects approximately 13-27% of the adult population. This deformity alters force distribution and shock absorption, increasing mechanical load on the joints and muscles of the lower kinetic chain. Consequently, flat feet are often associated with foot pain, tendinopathies, and different musculoskeletal disorders in the knees, hips, and lumbar spine.
One of the main causes of flat foot deformity is dysfunction of the tibialis posterior (TP) tendon. This dysfunction leads to reduced muscle strength, decreased neuromuscular activation of the foot invertors and plantar flexors, and subsequent lowering of the navicular bone, resulting in a reduced MLA height. Strengthening the m. TP not only maintains arch position but also improves gait efficiency by reducing compensatory activation of other muscles. This muscle is considered as the strongest foot invertor and has the largest moment arm along the subtalar axis.
Recent research highlights that strengthening foot invertor muscles, particularly m. TP, can effectively increase height of the MLA. Conventional interventions include specific exercise programs and proprioceptive neuromuscular facilitation techniques. However, neuromuscular electrical stimulation used in previous studies did not showed significant increases in MLA height, partly due to pain and discomfort during deep muscle stimulation.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Single (Outcomes Assessor)
盲法说明
The radiologist and the investigator responsible for testing the strength of the foot invertor muscles will be blinded to group allocation and intervention status. The radiologist will perform all ultrasound assessments of the foot invertor muscles and the height of the medial longitudinal arch, while the investigator will conduct standardized isometric strength measurements of the subtalar joint invertor muscles using a custom isometric dynamometer designed to measure torque along the subtalar axis. Both assessors will remain unaware of whether participants receive active rPMS or no stimulation.
入排标准
- 年龄范围
- 18 Years 至 50 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Age between 18 and 50 years,
- •functionally flat feet of participants.
排除标准
- •Acute leg injuries,
- •diabetes,
- •vascular disorders of the lower limbs,
- •open wounds or skin lesions on the lower leg or foot,
- •participants with metal implants near the stimulation site,
- •cardiac pacemaker,
- •other orthopedic or neurological conditions that could affect the study results or pose a health risk to the participants.
研究组 & 干预措施
rPMS Stimulation Group
Subjects in this group will receive repetitive peripheral magnetic stimulation (rPMS) of the foot invertor muscles three times per week for 12 weeks. Stimulation will be applied to the upper third of the anteromedial side of the shin. Intrinsic foot muscles will be simultaneously stimulated using a foot stimulator, with the nondominant foot placed on the stimulation platform. Participants in the experimental group will complete ultrasound imaging, navicular drop assessment, clinical evaluation of the plantar arch index, and isometric strength testing of the foot invertor muscles at three time points: before the intervention (baseline), after 6 weeks, and after 12-week stimulation period.
干预措施: Repetitive Peripheral Magnetic Stimulation (rPMS) (Device)
Control Group (no stimulation)
Subjects in control group will not receive any stimulation but will undergo the same measurement procedures as the experimental group, including ultrasound imaging, navicular drop assessment, clinical evaluation of the plantar arch index, and isometric strength testing of the foot invertor muscles before and after the 6- and 12-week period.
结局指标
主要结局
Change in medial longitudinal arch height
时间窗: Baseline (Day 1), Week 6, Week 12
Measuring dynamic navicular drop assessment during the stance phase of gait.
次要结局
- Change in isometric inversion torque of the stimulated foot(Baseline (Day 1), Week 6, Week 12)
研究者
Ales Dolenec
Associate Professor, Faculty of Sport, University of Ljubljana
University of Ljubljana