The role of neural tension in hamstring flexibility

Resistance to stretch, electromyographic (EMG) response to stretch, stretch discomfort and maximum range of motion (ROM) were measured during passive hamstring stretches performed in the slump test position (neural tension stretch) and in the upright position (neutral stretch) in eight healthy subjects. Stretches were performed on an isokinetic dynamometer at 5°/s with the test thigh flexed 40° above the horizontal, and the seat back at 90° to the horizontal. Surface EMG signals were recorded from the medial and lateral hamstrings during stretches. Knees were passively extended to maximum stretch tolerance with test order (neural tension vs neutral) alternated between legs. For neural tension stretches, the cervical and thoracic spine were manually flexed. Maximum ROM was 8° less for the neural tension stretch vs the neutral stretch (P<0.01). Resistance to stretch was 14–15% higher for the neural tension stretch vs the neutral stretch (P<0.001) at common joint angles in the final third of ROM. Stretch discomfort and EMG response were unaffected by neural tension. In conclusion, an increased passive resistance to stretch with the addition of neural tension during passive hamstring stretch despite no change in the EMG response indicates that passive extensibility of neural tissues can limit hamstring flexibility.

[1]  M. McHugh,et al.  To stretch or not to stretch: the role of stretching in injury prevention and performance , 2009, Scandinavian journal of medicine & science in sports.

[2]  Wim Dankaerts,et al.  Effect of Different Upright Sitting Postures on Spinal-Pelvic Curvature and Trunk Muscle Activation in a Pain-Free Population , 2006, Spine.

[3]  T. Housh,et al.  The acute effects of static stretching on peak torque, mean power output, electromyography, and mechanomyography , 2005, European Journal of Applied Physiology.

[4]  M. Voigt,et al.  Modification of stretch tolerance in a stooping position , 2004, Scandinavian journal of medicine & science in sports.

[5]  J. Stephenson.  To Stretch or Not to Stretch , 2002 .

[6]  S. Gandevia,et al.  Change in length of relaxed muscle fascicles and tendons with knee and ankle movement in humans , 2002, The Journal of physiology.

[7]  Hiroaki Kanehisa,et al.  Is passive stiffness in human muscles related to the elasticity of tendon structures? , 2001, European Journal of Applied Physiology.

[8]  P V Komi,et al.  Altered reflex sensitivity after repeated and prolonged passive muscle stretching. , 1999, Journal of applied physiology.

[9]  M. McHugh,et al.  The role of mechanical and neural restraints to joint range of motion during passive stretch. , 1998, Medicine and science in sports and exercise.

[10]  E K Johnson,et al.  The slump test: the effects of head and lower extremity position on knee extension. , 1997, The Journal of orthopaedic and sports physical therapy.

[11]  E B Simonsen,et al.  Determinants of musculoskeletal flexibility: viscoelastic properties, cross‐sectional area, EMG and stretch tolerance , 1997, Scandinavian journal of medicine & science in sports.

[12]  D. Perrin,et al.  Comparison of nonballistic active knee extension in neural slump position and static stretch techniques on hamstring flexibility. , 1997, The Journal of orthopaedic and sports physical therapy.

[13]  C. Briggs,et al.  Relationship between the cervical component of the slump test and change in hamstring muscle tension. , 1997, Manual therapy.

[14]  M. Kjaer,et al.  Viscoelastic stress relaxation during static stretch in human skeletal muscle in the absence of EMG activity , 1996, Scandinavian journal of medicine & science in sports.

[15]  E B Simonsen,et al.  Viscoelastic response to repeated static stretching in the human hamstring muscle , 1995, Scandinavian journal of medicine & science in sports.

[16]  J A Nicholas,et al.  Viscoelastic stress relaxation in human skeletal muscle. , 1992, Medicine and science in sports and exercise.

[17]  White Ma,et al.  The slump test. , 1992, American Journal of Occupational Therapy.

[18]  C. Kornberg,et al.  The effect of stretching neural structures on grade one hamstring injuries. , 1989, The Journal of orthopaedic and sports physical therapy.

[19]  B. Etnyre,et al.  Antagonist muscle activity during stretching: a paradox re-assessed. , 1988, Medicine and science in sports and exercise.

[20]  A. Magid,et al.  Myofibrils bear most of the resting tension in frog skeletal muscle. , 1985, Science.

[21]  P. Komi,et al.  HIGHLIGHTED TOPIC Neural Control of Movement Neural and mechanical responses of the triceps surae muscle group after 1 h of repeated fast passive stretches , 2004 .

[22]  K. George,et al.  Adverse neural tension: a factor in repetitive hamstring strain? , 1998, The Journal of orthopaedic and sports physical therapy.

[23]  P. Purslow,et al.  Strain-induced reorientation of an intramuscular connective tissue network: implications for passive muscle elasticity. , 1989, Journal of biomechanics.