Acute Effects of Neurodynamic Stretching on Muscle-tendon Complex

University of Burgundy21 enrolled

Overview

Neurodynamic mobilization techniques are widely applied in rehabilitation and physiotherapy to enhance the mobility and function of peripheral nerves. Two main approaches are distinguished. Nerve tensioning and nerve flossing. They both involve proximal and distal joint movements to induce greater neural sliding while avoiding excessive tensile stress. However, contradictory findings on neurodynamic techniques highlighted the current lack of consensus regarding these techniques. Moreover, neurodynamic techniques are of interest for patients, it appeared it could also be applied in healthy individuals and more particularly in athletes. Accordingly, the primary objective of the present study was to determine the immediate effect of two neurodynamic mobilization techniques (flossing vs. tensioning) on the sciatic nerve and hamstring tissues using the shear wave elastography (SWE, a form of ultrasonography).

Neurodynamic mobilization techniques are frequently applied in rehabilitation settings to enhance the mobility and function of peripheral nerves, particularly in the management of neuropathic pain such as carpal tunnel syndrome, radiculopathies, or sciatica. Two main approaches are distinguished. Nerve tensioning involves maintaining the nerve stretched at the end of the joint range of motion with relatively limited excursion. It is similar to a static stretching intervention but with distal (ankle) and proximal (cervical) tensions. Nerve flossing (also termed gliding or sliders), consists of alternating proximal and distal joint movements to induce greater neural sliding while avoiding excessive tensile stress. However, contradictory findings on neurodynamic techniques highlighted the current lack of consensus regarding the acute effects of the different possible neurodynamic techniques on sciatic nerves, particularly in healthy tissues. Moreover, neurodynamic techniques are of interest for patients, it appeared it could also be applied in healthy individuals and more particularly in athletes. Performed in patients, healthy or athletes, no study has compared both tensioning or flossing techniques. Moreover, because these techniques involved nerve mobilisation, the intensity should have a main effect of its efficiency. Accordingly, the primary objective of the present study was to determine the immediate effect of two neurodynamic mobilization techniques (flossing vs. tensioning) on the sciatic nerve and hamstring tissues using the shear wave elastography (SWE). This method has been shown reliable to provide non-invasive real-time assessments of soft tissues elastic properties. The secondary aim was to determine the effects of stretching intensity (at the point of pain threshold or below).

Interventions

Maximal static stretchingOTHER

Static stretching was applied at pain threshold on hamstring muscles and repeated 5 times during 60s at the point of pain. Static stretching mainly focused muscle-tendon tissues.

Submaximal static stretchingOTHER

Static stretching was applied 10% below pain threshold on hamstring muscles and repeated 5 times during 60s at the point of pain. Static stretching mainly focused muscle-tendon tissues.

Maximal neurodynamic tensioningOTHER

Neurodynamic tensioning was applied at pain threshold on hamstring muscles and repeated 5 times during 60s at the point of pain. During the neurodynamic conditions, head and ankle movement permitted to mobilize nerve tissues. Tensioning is maintaining the position.

Submaximal neurodynamic tensioningOTHER

Neurodynamic tensioning was applied 10% below pain threshold on hamstring muscles and repeated 5 times during 60s at the point of pain. During the neurodynamic conditions, head and ankle movement permitted to mobilize nerve tissues. Tensioning is maintaining the position.

Maximal neurodynamic flossingOTHER

Neurodynamic flossing was applied at pain threshold on hamstring muscles and repeated 5 times during 60s at the point of pain. During the neurodynamic conditions, head and ankle movement permitted to mobilize nerve tissues. Flossing is the alternation of these movements every 2 seconds.

Submaximal neurodynamic flossingOTHER

Neurodynamic flossing was applied 10% below pain threshold on hamstring muscles and repeated 5 times during 60s at the point of pain. During the neurodynamic conditions, head and ankle movement permitted to mobilize nerve tissues. Flossing is the alternation of these movements every 2 seconds.

Outcomes

Primary Outcomes

Nerve shear wave velocity using elastography

Shear wave velocity of the sciatic nerve will be evaluated by using an ultrasound (echography) device with a specific mode called "shear wave elastography". Briefly, the ultrasound probe will deliver an ultrasound wave. The propagation speed (called '"shear wave velocity") will be measured by the same probe. The greater the velocity is, the harder the tissue is.