The purpose of this research was to evaluate the effects of a long-term
static stretching program on flexibility and spinal reflexes in the
human soleus muscle. Day-to-day reliability over two days of H-reflex gain
(Hslp/Mslp) and pre-synaptic inhibition of spinal reflexes in the human
soleus was measured in an initial study. Thirty subjects (age=23.4 ± 3.9
yr, height=175.64 ± 10.87 cm, weight=84.5 ± 24.18 kg) with no history of
lower leg pathology and/or injury within the previous 12 months
volunteered. The slopes of the ascending portions of the H-reflex and M-wave
recruitment curves were used to evaluate H-reflex gain (Hslp/Mslp).
The mean soleus H-reflex from 10 conditioning stimulations and 10
unconditioned stimulations was used to calculate the amount of pre-synaptic
inhibition. Measurements of H-reflex gain and pre-synaptic
inhibition yielded test-retest reliability of R=.95 and R=.91, respectively.
The contribution of pre-synaptic and post-synaptic reciprocal
mechanisms in flexibility adaptations has not been measured during the
same study. A long-term static stretching program (5 times per week for 6
weeks) of the soleus implemented within an experimental group of 20
subjects was used as an intervention to measure both spinal control
flexibility changes. Additionally, 20 control subjects were measured that
did not participate in the stretching program. Passive ankle dorsiflexion,
Hmax/Mmax, H-reflex gain (Hslp/Mslp), pre-synaptic and post-synaptic
reciprocal mechanisms were measured at baseline, 3 weeks, and 6 weeks
for all 40 subjects. A 2 (Group) X 2 (Sex) X 3 (Time) mixed MANOVA with
Tukey HSD with (a<0.05) was used. Only ROM had a significant
interaction between Group and Time, whereas, a significant difference was
not detected in the other dependent variables. The experimental group
demonstrated significantly improved dorsiflexion ROM from baseline to 3
weeks (mean=6.2 ± .88, P<0.001), 3 weeks to 6 weeks (mean=4.9 ±
.84, P<0.001), and baseline to 6 weeks (mean=11.2 ± .91, P<0.001).
Consequently, the increase in flexibility by 42% after 30 stretching
sessions was not the result of spinal reflex changes. / Graduation date: 2006
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28867 |
| Date | 26 July 2005 |
| Creators | Hayes, Bradley T. |
| Contributors | Hoffman, Mark A. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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