The effects of rocker sole profiles on gait : implications for claudicants

Hutchins, SW

Abstract

Intermittent claudication (1C) is a vascular condition which limits the
distance subjects can walk before experiencing pain in the lower limb calf
muscles due to limitation of vascular supply. Orthotic intervention
evidenced in the literature has previously included the use of rocker
profiles or raised heels to increase the pain-free walking distance, but
variable results have been demonstrated. This study aims to design a
rocker profile with the specific objectives of increasing the pain free
walking distance demonstrated by claudicants and reducing their calf pain
once claudicating.
Method
Twelve volunteer healthy subjects, age range 25 to 54 years (mean: 32.7
+/- 11.3), initially undertook separate walking trials in gait laboratory
conditions with shoes adapted with three different rocker sole profiles; the
one-curve toe-only profile, the two-curve profile and the three-curve
profile, plus a shoe adapted with a moderate (12mm) heel raise.
Measurements and comparisons of gait kinetics and kinematics (Qualysis,
Sweden), and the electromyographical (EMG) activity (Noraxon, USA) of
the medial and lateral gastrocnemius muscles, plus that of soleus and
tibialis anterior, were undertaken. The most effective condition compared
to a baseline un-adapted shoe was then tested during walking trials with
claudicants (n=8, mean age 66 +/- 9 years) to ascertain its efficacy in
reducing the pain-free walking distance to claudication and the severity of
the pain once claudicating.
Results
All changes from the baseline shoe were set at a level of significance of
p<0.05 The three-curve rocker profile placed the ankle joint into a
relatively plantarflexed position compared to baseline at loading response
(/?=0.00), mid stance (p=0.00) and terminal stance (/?=0.00), and
significantly reduced total sagittal plane ankle range of motion compared
to baseline (/7=0.00). The moderate heel raise also induced ankle
plantarflexion at loading response (p=0.00) but increased ankle range of
motion during second rotational phase of gait (/?=0.00) compared to
baseline. The one-curve rocker profile induced a sagittal plane
dorsiflexion shift at the ankle during mid stance (/?=0.00). The three-curve
rocker profile was the most effective test condition in reducing both the
externally-applied ankle dorsiflexion moment (/?=0.00) and ankle power
generation (p=0.00) during stance phase of gait compared to baseline.
Changes to muscle EMG values by all the test conditions were not
statistically significant. Claudicant walking trials when wearing the three
curve rocker profile demonstrated a statistically significant increase in
pain-free walking distance to claudication (/?=0.00) and a reduction in
claudication pain once claudicating (/?=0.00).
Conclusion
This study demonstrates that a specifically-designed rocker profile can
significantly alter gait kinetics and kinematics and produce a statistically
different increase in the pain-free walking distance of claudicants whilst
also significantly reducing their pain levels once claudicating.

Citation

Hutchins, S. The effects of rocker sole profiles on gait : implications for claudicants. (Thesis). Salford : University of Salford

• Thesis Type: Thesis
• Deposit Date: Oct 3, 2012
• Award Date: Jan 1, 2007