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

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

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.

Study Overview

• Status: Recruiting
• Conditions: Hamstring Injury
• Intervention / Treatment: Other: Nordic Hamstring Exercises + SIS stimulation; Other: Plyometric traning + SIS stimulation; Other: Neuromuscular traning + SIS stimulation; Other: Super Inductive Stimulation (SIS) Intervention

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

• Study Type: Observational
• Enrollment (Estimated): 30

Contacts and Locations

• Study Contact: Name: Ewelina Perzanowska, PhD; Phone Number: 791597673; Email: ewelina.perzanowska@awf.gda.pl

Study Locations

• Poland
  • Gdansk, Poland, 80-336
    • Recruiting
    • Gdansk University of Physical Education and Sport
    • Contact: Ewelina Perzanowska, PhD; Phone Number: 791597673; Email: ewelina.perzanowska@awf.gda.pl

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

Physically active individuals aged 19-40 years, performing a minimum of two training sessions per week.

Description

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.

Study Plan

How is the study designed?

Number of groups / cohorts

4

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Nordic Hamstring Exercises + SIS stimulation; The participants will be randomly assigned to four research groups. The first research group will undergo a four-week Nordic Hamstring Exercise training program combined with Super Inductive Stimulation applied to the hamstring muscle group. The second research group will perform a four-week Nordic Hamstring Exercise training program. The third research group will undergo a four-week series of Super Inductive Stimulation sessions applied to the hamstring muscle group. The fourth group, which will serve as the control group, will not change their physical activity habits.	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.
Plyometric traning + SIS stimulation; The participants will be randomly assigned to four research groups. The first research group will undergo a four-week plyometric training program combined with Super Inductive Stimulation applied to the hamstring muscle group. The second research group will perform a four-week plyometric training program. The third research group will undergo a four-week series of Super Inductive Stimulation sessions applied to the hamstring muscle group. The fourth group, which will serve as the control group, will not change their physical activity habits.	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, multi-joint movements, and more complex techniques.
Neuromuscular traning + SIS stimulation; The participants will be randomly assigned to four research groups. The first research group will undergo a four-week neuromuscular training program combined with Super Inductive Stimulation applied to the hamstring muscle group. The second research group will perform a four-week neuromuscular training program. The third research group will undergo a four-week series of Super Inductive Stimulation sessions applied to the hamstring muscle group. The fourth group, which will serve as the control group, will not change their physical activity habits.	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, emphasizing the maintenance of proper posture on either one or both legs during multitask activities. In the third week, dynamic exercises on unstable surfaces are added, such as single-leg squats. In the final week, jumps and hops are incorporated. To further increase difficulty, additional load is introduced in the form of medicine balls weighing between 2 and 8 kilograms.
Super Inductive Stimulation (SIS) Intervention; Super Inductive Stimulation (SIS) uses a high-intensity electromagnetic field (28 kT/s). The stimulus, induced by a coil placed in the applicator, generates depolarization of neuromuscular tissue. As a result, SIS evokes an action potential in the neuromuscular tissue, leading to the strengthening of weakened muscles. Due to the methodology of this intervention, the procedures are performed once per week over a period of 4 weeks.	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

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Medial-Lateral Stability Index (MLSI)	Assessment of medial-lateral postural stability using a balance platform	Baseline and immediately post-intervention (Week 4)
Overall Stability Index (OSI)	Assessment of overall postural stability using a balance platform	Baseline and immediately post-intervention (Week 4)
Anteroposterior Stability Index (APSI)	Assessment of anteroposterior postural stability using a balance platform	Baseline and immediately post-intervention (Week 4)
Maximal hamstring muscle strength	Maximal voluntary strength of the hamstring muscles will be assessed bilaterally using a standardized strength testing protocol	Baseline and immediately post-intervention (Week 4)

Collaborators and Investigators

• Sponsor: Gdansk University of Physical Education and Sport
• Investigators: Study Chair: Ewelina Perzanowska, PhD, Department of Kinesytherapy

Study record dates

Study Major Dates

• Study Start (Actual): March 15, 2025
• Primary Completion (Estimated): May 1, 2026
• Study Completion (Estimated): May 1, 2026

Study Registration Dates

• First Submitted: September 11, 2025
• First Submitted That Met QC Criteria: March 19, 2026
• First Posted (Actual): March 25, 2026

Study Record Updates

• Last Update Posted (Actual): March 25, 2026
• Last Update Submitted That Met QC Criteria: March 19, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: neuromuscular; plyometric
• Additional Relevant MeSH Terms: Investigative Techniques; Methods
• Other Study ID Numbers: AWFiS/2025_9_EP

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No