Effects of Combining PNF With NMES in Young Basketball Players

NCT ID: NCT06648356

Last Updated: 2024-10-30

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 44 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-10-01
• Study Completion Date: 2024-10-23

Brief Summary

Hamstring muscle injuries are common in basketball and result in long periods of inactivity. This study aims to compare two different stretching programs to assess their effects on hamstring flexibility and, secondarily, on jumping ability in young basketball players. One program uses a special stretching technique called proprioceptive neuromuscular facilitation (PNF), while the other uses the same stretching but adds electrical stimulation (NMES).

Detailed Description

Hamstring strains are increasingly common in sports, particularly in football and professional basketball, where they are the fourth most frequent injury. Stretching, especially when combined with techniques like proprioceptive neuromuscular facilitation (PNF), is a key method used to reduce the risk of these injuries. PNF, which involves alternating stretches with muscle contractions, is widely regarded for improving muscle flexibility. Recently, stretching combined with neuromuscular electrical stimulation (NMES) has also shown promise for increasing flexibility. A variant of PNF called contract-relax PNF (crPNF) has been proposed, where NMES is applied during the contraction phase to further enhance flexibility gains. However, there are no studies on the short-term effects of crPNF and crPNF + NMES in young male basketball players, a group known for higher degrees of hamstring shortening.

This study aims to compare the short-term effects of crPNF and crPNF + NMES on hamstring flexibility in young male basketball players and assess whether one technique is superior to the other. A secondary goal is to determine if either stretching protocol negatively impacts vertical jump ability, an important skill in basketball.

Conditions

Hamstring Flexibility

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

contract-relax proprioceptive neuromuscular facilitation (crPNF)

Participants in this group performed a stretching protocol using contract-relax proprioceptive neuromuscular facilitation (crPNF). The participants are placed in a long sitting position with maximum knee extension possible until a moderate-strong stretch sensation is felt, without pain. The stretch lasts for 20 seconds, followed by a maximal voluntary isometric contraction of the hamstrings for 5 seconds. Three stretch-contraction cycles are completed. One researcher maintains the stretch position, while a second researcher controls the stretching and contraction times.

Group Type: ACTIVE_COMPARATOR

Contract-Relax PNF (crPNF)

Intervention Type: OTHER

The crPNF Group engages in an isolated contract-relax proprioceptive neuromuscular facilitation (crPNF) stretching protocol. Participants are positioned in a long sitting posture with maximum knee extension until they feel a moderate-strong stretch sensation, without pain. Each stretch lasts for 20 seconds, followed by a 5-second maximal voluntary isometric contraction of the hamstrings. Participants complete three cycles of stretch and contraction. One researcher maintains the stretch position while a second researcher controls the timing of the stretching and contractions.

Neuromuscular Electrical Stimulation (NMES + crPNF)

The participants follow the same stretching protocol but with neuromuscular electrical stimulation (NMES) added. Electrical stimulation (50Hz, 300 µs pulse width) is applied using an Enraf Nonius TensMed S82 device. Two 5x9 cm electrodes are placed on the hamstrings, and participants adjust the current to a moderate-strong, but painless, contraction. One researcher maintains the stretch, while another adjusts the current intensity and controls the timing of the stretching and contraction.

Group Type: EXPERIMENTAL

Neuromuscular electrical stimulation (NMES)

Intervention Type: OTHER

Neuromuscular electrical stimulation (NMES) is applied during an isometric contraction. The NMES uses a symmetrical biphasic rectangular pulse (50Hz frequency and 300 µs phase width) delivered through an Enraf Nonius TensMed S82 electrostimulator. Two 5x9 cm electrodes are placed on the hamstrings, and participants adjust the current to a moderate-strong, yet painless, contraction level. During the intervention, one researcher maintains the stretch position while another researcher controls the current intensity and monitors the timing of both stretching and contractions.

Contract-Relax PNF (crPNF)

Intervention Type: OTHER

The crPNF Group engages in an isolated contract-relax proprioceptive neuromuscular facilitation (crPNF) stretching protocol. Participants are positioned in a long sitting posture with maximum knee extension until they feel a moderate-strong stretch sensation, without pain. Each stretch lasts for 20 seconds, followed by a 5-second maximal voluntary isometric contraction of the hamstrings. Participants complete three cycles of stretch and contraction. One researcher maintains the stretch position while a second researcher controls the timing of the stretching and contractions.

Interventions

Neuromuscular electrical stimulation (NMES)

Neuromuscular electrical stimulation (NMES) is applied during an isometric contraction. The NMES uses a symmetrical biphasic rectangular pulse (50Hz frequency and 300 µs phase width) delivered through an Enraf Nonius TensMed S82 electrostimulator. Two 5x9 cm electrodes are placed on the hamstrings, and participants adjust the current to a moderate-strong, yet painless, contraction level. During the intervention, one researcher maintains the stretch position while another researcher controls the current intensity and monitors the timing of both stretching and contractions.

Intervention Type: OTHER

Contract-Relax PNF (crPNF)

The crPNF Group engages in an isolated contract-relax proprioceptive neuromuscular facilitation (crPNF) stretching protocol. Participants are positioned in a long sitting posture with maximum knee extension until they feel a moderate-strong stretch sensation, without pain. Each stretch lasts for 20 seconds, followed by a 5-second maximal voluntary isometric contraction of the hamstrings. Participants complete three cycles of stretch and contraction. One researcher maintains the stretch position while a second researcher controls the timing of the stretching and contractions.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Active basketball players who train at least 3 days a week
• Ages between 11 and 18 years
• Male gender

Exclusion Criteria

• Participation in an organized hamstring stretching program
• Presence of low back pain
• Hamstring muscle injuries in the last 6 months
• Spinal or abdominal surgeries in the last 6 months

• Minimum Eligible Age: 11 Years
• Maximum Eligible Age: 18 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: Yes

Sponsors

Cardenal Herrera University

OTHER

Sponsor Role: lead

Responsible Party

Juan F. Lisón Párraga, Dr

Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Juan Francisco Lisón Párraga, Dr

Role: PRINCIPAL_INVESTIGATOR

Cardenal Herrera University

Locations

University Ceu Cardenal Herrera

Alfara del Patriarca, Valencia, Spain

Countries

Spain

Other Identifiers

UNIVERSITY CARDENAL HERRERA-86

Identifier Type: -

Identifier Source: org_study_id