gms | German Medical Science

7th EFSMA – European Congress of Sports Medicine, 3rd Central European Congress of Physical Medicine and Rehabilitation, Annual Assembly of the German and the Austrian Society of Physical Medicine and Rehabilitation

Austrian Society of Physical Medicine and Rehabilitation

26.-29.10.2011, Salzburg, Österreich

Intersession reliability of H-reflex measurements in treadmill walking

Meeting Abstract

7th EFSMA – European Congress of Sports Medicine, 3rd Central European Congress of Physical Medicine and Rehabilitation. Salzburg, 26.-29.10.2011. Düsseldorf: German Medical Science GMS Publishing House; 2011. Doc11esm221

DOI: 10.3205/11esm221, URN: urn:nbn:de:0183-11esm2213

Veröffentlicht: 24. Oktober 2011

© 2011 König et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielfältigt, verbreitet und öffentlich zugänglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Objective: H-reflex measures are commonly used in sports and exercise science. Minimum muscle activation is necessary to evoke the H-reflex. Therefore multiple studies investigated reliability of the measure in different static body positions [1], [2]. Particularly, in dynamic conditions the correct reproduction of background muscle activation and posture is essential for reliability [3]. Since walking is unlikely to alter noticeably between sessions, it could serve as standard setup for H-reflex measurements at the lower extremity. Consequently, intersession reliability of soleus muscle H-reflex during treadmill walking was investigated.

Material/Methods: 7 young and healthy (2 female, 5 male) participants were measured twice during an average of 47 (±9) days. Subjects performed walking trials on a treadmill at 5 km/h. The stimulating electrode was placed on the tibial nerve in the popliteal fossa. EMG was recorded from the soleus muscle. To synchronize the stimulus to the gait cycle initial heel strike was detected with a plantar pressure sole. A 300 ms delay was used to stimulate in midstance. Finally the recruitment curve was created (Square-impulse: 500 µs duration; Stimulation-interval: 10 s; Increase of stimulation intensity: 0.2 mA). Hence, maximum H-reflex amplitude and M-wave amplitude was obtained and Hmax/Mmax-Ratio was calculated. Intersession reliability was assessed by calculation of intraclass and Pearson’s correlation-coefficient, test-retest variability and Bland and Altman’s 95% limits of agreement criterion.

Results: The Hmax/Mmax-Ratio ranged from 0.24-0.54. Data reveals good intraclass (ICC=0.89) and Pearson’s correlation-coefficients (r=0.95). The TRV was 13.01% (±11.8). The reliability criterion by Bland & Altman was fulfilled (100%).

Conclusion: H-reflex measurements in dynamic condition reveal high intersession reliability. Although gait increases degrees of freedom (gait speed, step length, step width, loading conditions, etc.), reliability of dynamic and static measurements is almost equal [2], [4], [5]. The H-reflex during walking can serve as a reliable measurement tool in many sports and exercise contexts.


References

1.
Ali A, Sabbahi MA. Test-retest reliability of the soleus H-reflex in three different positions. Electromyogr. Clin Neurophysiol. 2001;41(4):209-14.
2.
Hopkins JT, Ingersoll CD, Cordova ML, Edwards JE. Intrasession and intersession reliability of the soleus H-reflex in supine and standing positions. Electromyogr Clin Neurophysiol. 2000;40(2):89-94.
3.
Chen YS, Zhou S, Cartwright C, Crowley Z, Baglin R, Wang F. Test-retest reliability of the soleus H-reflex is affected by joint positions and muscle force levels. J Electromyogr Kinesiol. 2010;20(5):980-7.
4.
Palmieri TM, Hoffman MA, Ingersoll CD. Intersession reliability for H-reflex measurements arising from the soleus, peroneal, and tibialis anterior musculature. International Journal of Neuroscience. 2002;112(7):841-50.
5.
Phadke CP, Thompson FJ, Trimble MH, Behrman AL, Kukulka CG. Reliability of soleus H-reflexes in standing and walking post-incomplete spinal cord injury. Int J Neurosci. 2010;120(2):128-36.