THE EFFECTS OF NEUROMUSCULAR ACTIVATION OF THE POSTERIOR CHAIN ON THE FLEXIBILITY OF HAMSTRINGS IN HEALTHY SUBJECTS

N. El Khazen Nseir¹, E. Dagher², M. Hanania², J. Tawk², D. Wakim², P. Breidy², L. Rahy³

¹Waterbear SAL and Saint Joseph University, Institute of Physical Therapy, Beirut, Lebanon, ²Saint Joseph University, Institute of Physical Therapy, Beirut, Lebanon, ³Waterbear, Physiotherapy, Beirut, Lebanon

Background: Hamstring flexibility is essential for proper performance of functional activities. Static muscle stretching is one of the standard techniques to increase muscle flexibility but stretching recommendations are still unclear in the literature. A tight muscle is a weak muscle, therefore, the Neurac technique, which stands for neuromuscular activation, is an interesting method to increase the flexibility.

Purpose: The aim of this study is to evaluate the effectiveness of neuromuscular activation of the posterior chain on the flexibility of the hamstrings.

Methods: 61 subjects are recruited, including 33 men and 28 women. 3 tests are carried out for the evaluation of the flexibility of the hamstrings in 3 stages, before the treatment, after the treatment, and 7 days following the treatment. The tests are the Sit and reach test, the multi-segmental flexion, and the Passive Knee Extension Test (PKET). The treatment technique performed is Neurac that stands for neuromuscular activation.

Results: The results show an improvement in hamstring flexibility according to the 3 tests: the sit and each test (89%), the multi-segmental flexion (49%), PKET (90%) directly after the treatment and after 7 days compared to the pre-treatment. There is a slight deterioration in flexibility between post-treatment and D7, but this difference is not significant (p>0.05). Flexibility is better in women and in younger people, however, age has no relation to the effectiveness of the treatment.

Conclusions: Following the results obtained, we can conclude that the use of the Neurac technique for activating the posterior chain improves the flexibility of the hamstrings, not only in the short term, but also in the long term. The Neurac technique should be considered as a treatment tool for people who aim to increase their muscle flexibility regardless of their age.

Implications: Understand that a tight muscle is a weak muscle and therapists should strengthen it not only stretch it for sustainable results. Learn how to use the right muscle, at the right time, in the right amount for an adequate neuromuscular activation while understanding that the number of muscle spindles doesn't change with age which gives the chance of improvement to everybody regardless the age.

Funding acknowledgements: No funding

Keywords:
Neuromuscular activation
Flexibility
Posterior chain

Topics:
Musculoskeletal: lower limb

Did this work require ethics approval? Yes

Institution: Saint Joseph University - Beirut, Lebanon

Committee: USJ Ethics committee

Ethics number: USJ-2022-75