Comparison of the Effects of Selected Training Methods and SIS Stimulation on Balance, Motor Tests, and Strength

Official title

Comparison of the Effects of Selected Training Methods (Neuromuscular Training, Plyometric Training, and Nordic Hamstring Exercise) and SIS Stimulation on Balance, Motor Performance Tests, and Lower Limb Strength

Overview

The purpose of this study is to evaluate the effects of four-week training interventions-Nordic Hamstring Exercise, plyometric training, and neuromuscular training-combined with Super Inductive Stimulation (SIS) on hamstring muscle strength, balance, and motor performance.

Detailed description

This randomized controlled study evaluates the effects of three four-week training interventions-Nordic Hamstring Exercise, plyometric training, and neuromuscular training-performed alone or in combination with Super Inductive Stimulation (SIS) in physically active adults.

The study is conducted in three independent stages, each corresponding to a specific training modality. Within each stage, participants are randomly allocated to one of four parallel groups: (1) training combined with SIS, (2) training only, (3) SIS only, or (4) control (no change in habitual physical activity). This design enables assessment of both isolated and combined effects of exercise and electromagnetic stimulation.

All interventions are delivered over a four-week period under supervision. Training protocols are standardized and specific to the intervention type, targeting eccentric strength (Nordic Hamstring Exercise), explosive performance (plyometric training), or neuromuscular control (neuromuscular training).

SIS is applied to the hamstring muscle group using a high-intensity electromagnetic stimulation device, with standardized parameters across participants.

A familiarization phase is conducted prior to the intervention to ensure consistency in procedures. Adherence and protocol compliance are monitored throughout the study.

This study aims to determine the relative and combined effectiveness of these interventions in improving neuromuscular performance in physically active individuals

Interventions

• Other Nordic Hamstring Exercises + SIS stimulation
  Nordic Hamstring Exercise training lasts 4 weeks, during which the participant performs 3 sets, each consisting of 3 repetitions of the NHE. After each set, a 2-minute passive rest period follows, during which the participant recovers. In the first week, the participant trains under the supervision of the instructor, while in the following three weeks the exercises are performed at home after prior instruction.
• Other Plyometric traning + SIS stimulation
  The intervention lasts 4 weeks, during which participants train three times per week. The program consists of single-leg and double-leg jumps, vertical jumps, lateral jumps, and forward jumps, all performed on a stable surface. A principle of progressive overload is applied, with gradual increases in training intensity, volume, and jump height. The progression begins with lower intensity exercises, single-joint movements, and less complex techniques, and advances to higher intensity exercises, m
• Other Neuromuscular traning + SIS stimulation
  The intervention lasts 4 weeks, with participants training three times per week. The program focuses on improving dynamic stability and incorporates the use of BOSU equipment. Exercises include multitask movements performed on unstable surfaces as well as exercises with eyes closed. During the first week, exercises are performed on a stable surface to improve balance while standing on one leg with eyes open and closed. In the following weeks, exercises on unstable surfaces are introduced, emphas
• Other Super Inductive Stimulation (SIS) Intervention
  uses a high-intensity electromagnetic field (28 kT/s). The stimulus, induced by a coil placed in the applicator, generates depolarization of neuromuscular tissue

Primary outcome measures

• Medial-Lateral Stability Index (MLSI) [Time frame: Baseline and immediately post-intervention (Week 4)]
• Overall Stability Index (OSI) [Time frame: Baseline and immediately post-intervention (Week 4)]
• Anteroposterior Stability Index (APSI) [Time frame: Baseline and immediately post-intervention (Week 4)]
• Maximal hamstring muscle strength [Time frame: Baseline and immediately post-intervention (Week 4)]

Eligibility criteria

Inclusion criteria

• Healthy individuals aged 19-40,
• Without injuries,
• Physically active persons, athletes.

Exclusion criteria

• periods of peak training load specific to the athlete's discipline,
• evidence of overload-related pathology in the knee, hip, or lumbosacral joints,
• the presence of any pain symptoms,
• clinically relevant muscle fatigue or indicators of overtraining,
• engagement in strength-based sports within several weeks preceding competition,
• active inflammatory conditions involving osseous, articular, or ligamentous structures of the lower limbs,
• a history of injury or surgical intervention within the 6 months prior to the study intervention.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Study design

Observational model

Other

Study locations

Poland · 1 center

• Gdansk University of Physical Education and Sport — Gdansk

Identifiers

NCT: NCT07492732 · AWFiS/2025_9_EP

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗