Nicola A. Maffiuletti Director, Neuromuscular Research Laboratory, Schulthess Clinic, Zurich, Switzerland. - Assessment of hamstring muscle function: where are we going? (6th MuscleTech Network Workshop) 13th and 14th October, Barcelona

1. Nicola A. Maffiuletti
Neuromuscular Research Laboratory, Schulthess Clinic, Zurich (Switzerland)
Muscle Tech Network Workshop
Barcelona, 13 October 2014

2. Career of an athlete

3. • strength
• optimal angle
• fatigue
Assessment
Treatment
Muscle weakness

4. • strength
• optimal angle
• fatigue
Assessment
Treatment
Mechanisms underlying
muscle weakness

5. 1
2
Clinician
Researcher

6. 79
72
56
51
32
17
0 10 20 30 40 50 60 70 80 90
Normative data
H:Q functional ratio
Subjective feeling
H:Q conventional ratio
Previous evaluation
Bilateral asymmetry
% physicians
Delvaux et al. JSSM 2014

7. Tool
Dynamometer (load cells)
Test
Bilateral nordic H
Outcome
Eccentric strength
Cut-off
<3.16-3.45 N/kg
Alternative
Optimal angle…
Opar et al. JOSPT 2013 & MSSE 2014
Ditroilo et al. JEK 2013 & Mendiguchia et al. JSCR 2013

8. Tool
Dynamometer (isokinetic)
Test
H eccentric
Outcome
Eccentric torque
Cut-off
> 10%
46
72
83
Alternative
Rate of torque development Delvaux et al. JSSM 2014
Lee et al. MSSE 2009
Opar et al. AJSM 2013
H
a
m
s
t
r
i
n
g
% physicians
Eccentric
Isometric
<5%
<10%
<15%
<20%
Concentric
Uninjured
Injured

9. Tool
Dynamometer (isokinetic)
Test
H eccentric + Q concentric
Outcome
H:Q functional ratio
Cut-off
< 80%
Alternative
H:Q explosive ratio
Croisier et al. AJSM 2002
Hannah et al. MSSE 2014

10. Tool
60-cm box
Test
Single-leg bridge
Outcome
No. reps
Cut-off
< 25 reps
Freckleton et al. BJSM 2014
Zebis et al. BJSM 2013

12. Quadriceps EMD 23 ± 3 ms
Hamstring EMD 44 ± 8 ms
Hannah et al. MSSE 2014
Tools
Dynamometer - sEMG
Procedure
Explosive isom. contractions
Cut-off
> 10% (bilateral)
Mechanisms
↓ conduction velocity
↓ E-C coupling
Complement
High density sEMG

13. Quadriceps torque (Nm)
160
100
140
120
100
80
60
40
20
0
100%
Sedory et al. JAT 2007
Minshull et al. JEK 2008
Buhmann BJSM 2014 (a)
Tools
Dynamometer - Stimulator
Procedure
Twitch interpolation
Cut-off
< 90%
Mechanisms
↓ recruitment
↓ firing frequency
Torque (Nm)
Complement
TMS vs. PS for supraspinal/spinal
80%
90
80
70
60
50
Uninjured Injured
Voluntary activation level (%)
Concentric Eccentric

16. Bellumori et al. EBR 2011
Casartelli et al. MN 2014

17. Nicola A. Maffiuletti
Neuromuscular Research Laboratory
Schulthess Clinic, Zurich, Switzerland
mna@kws.ch