Neurological maladaptations following hamstring strain injury.

1. Neurological maladaptations
following hamstring strain
injury
Rob Buhmann
Assoc. Prof. Tony Shield- Primary supervisor
Prof. Graham Kerr- Associate supervisor

2. Mechanism of Injury
Higashihara et al. 2014nEMG
MTULength

3. So why is injury a
problem?
12 months +
Rate of torque
development (Opar
et al. 2013)
Maximal eccentric
EMG (Sole et al. 2011)
Maximal eccentric
strength and EMG
(Opar et al. 2013)
Activity during
Nordics (Bourne
et al. 2015)
Biceps femoris long
head fascicle length
(Timmins et al. 2016)
3 months 6 months 9 months

4. An explanation for re-
injury risk…
Fyfe et al. 2013

5. VA pathways that may be
altered
Hodges & Tucker 2011
?
?

6. Assessing VA

7. Reflex pathways

8. Participants
n Age (± SD) Weight
(± SD)
Height
(± SD)
Control 13 23.9yrs
(4.3)
80.0kg
(8.8)
177.0cm
(6.9)
Injured* 12 22.2yrs
(2.6)
79.2kg
(10.1)
180.3cm
(9.7)
* AVG Time since injury = 6.8 months

9. Voluntary activation
2.46
1.81

10. Stretch Reflex
1.20
1.23

11. Tendon reflex
1.36
1.21

12. So what, who cares?
Driver
Motor Computer
• Less output from motor
(~22% more force from
muscle with stimulation)
• Reduced sensitivity of
receptors or computer?
• Stress/strain on active
muscle fibres during sprinting
gait?

13. Training implications
Alternative methods for
stimulation of voluntary
activation?

14. Conclusion
Reductions in %VA in previously
injured participants
May be underpinned by
alterations in spinal reflex
loops
Findings may partly explain
injury recurrence

15. Thanks for listening!
Rob Buhmann
r.buhmann@qut.edu.au
@BuhmannRobert