Effects of Combining PNF With NMES in Young Basketball Players (PNF+NMES)

Cardenal Herrera University

Status: Completed

Conditions: Hamstring Flexibility

Treatments: Other: Neuromuscular electrical stimulation (NMES); Other: Contract-Relax PNF (crPNF)

Study type: Interventional

Funder types: Other

Identifiers

NCT06648356

UNIVERSITY CARDENAL HERRERA-86

Details and patient eligibility

About

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).

Full 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.

Enrollment: 44 patients

Sex: Male

Ages: 11 to 18 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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44 participants in 2 patient groups

contract-relax proprioceptive neuromuscular facilitation (crPNF)

Active Comparator group

Description:

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.

Treatment:

Other: Contract-Relax PNF (crPNF)

Neuromuscular Electrical Stimulation (NMES + crPNF)

Experimental group

Description:

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.

Treatment:

Other: Contract-Relax PNF (crPNF)

Other: Neuromuscular electrical stimulation (NMES)