Ankle Plantar Flexor Torque

Knee Flexor Torque

Hip Flexor Torque

Ankle Power Generated

Knee Power Generated

Hip Power Generated

0

0.5

1

1.5

2

2.5

INTRODUCTION

Gait Biomechanics Are Not Improved Following Supervised Treadmill Exercise In Patients With Peripheral Arterial Disease

Bryon C. Applequist1, Shane R. Wurdeman1, Iraklis I. Pipinos2,3 , Jason M. Johanning2,3, Sara A. Myers1

METHODS

DISCUSSION

ACKNOWLEDGEMENTS

• Intermittent claudication is the primary symptom of peripheral arterial disease (PAD) that occurs because blockages in the lower extremity arteries hinder blood flow to the legs. [1](Figure 1)•Current conservative treatment for patients with PAD consists of supervised treadmill walking exercise (STW).•After STW, patients with PAD exhibit improvement in maximum walking distances. [2]•Little is known about mechanistic changes to gait following standard treadmill exercise in patients with PAD.

RESULTS

Funding was provided by VA RR&D (IT01RX000604) and NIH (1RO1AG034995).

Travel funding provided by the American Society of Biomechanics.

•In agreement with the previous literature, absolute claudication distance significantly increased post STW.•No significant differences between baseline and post STW were detected for joint torques and powers, or lower extremity strength.•STW appears to address a cardiovascular mechanism in PAD and may only be helping to improve walking economy and/or pain tolerance.•Lack of improvements in gait biomechanics and lower extremity strength suggests the muscular myopathy present in patients with PAD is unchanged following STW.•The lack of functional training may be reinforcing poor mechanics, which will continue to hinder patient function.•Future investigation should include the impact of functional exercises that address problems identified in PAD muscle, on gait biomechanics.

n Age Mass HeightPatients 15 66.0 + 1.9 yrs 89.2 + 5.0 kg 175 + 2.24 cm

•Purpose: To determine the effectiveness of STW on walking distance, gait biomechanics, and lower extremity strength in patients with PAD. Hypothesis: Claudication distances will increase following supervised treadmill walking. Gait biomechanics and lower extremity strength will also improve following STW.

Pre-STW

REFERENCES1. Scherer S. et al., (2003) Cortland Forum, 2(16):22-8. 2. Montgomery and Gardner. (1998) J Am. Ger Soc, 46(6):706-11

Five trials of walking were

collected for each limb

Each subject rested for one

minute between each trial

1Biomechanics Research Building, University of Nebraska at Omaha, Omaha, NE 2Omaha Veterans’ Affairs Medical Center, Omaha, NE

3University of Nebraska Medical Center, Omaha, NE

Figure 1. Atherosclerotic blockages in the arteries limiting oxygenated blood to the lower extremity.

Peak isometric plantar flexor torque was collected using an isokinetic dynamometer. Walking distances were determined using a

progressive treadmill walking test.

Patients performed gait evaluations before and after participating in a 12-week supervised treadmill exercise intervention.

Post-STW

Absolute Claudication Distance (m)

Ankle Plantar Flexion Torque

(Nm/kg)

Knee Flexor Torque (Nm/kg)

Hip Flexor Torque (Nm/kg)

Ankle Power Generated

(W/kg)

Knee Power Generated

(W/kg)

Hip Power Generated

(W/kg)

Peak Plantar Flexor Strength

(ft/lbs)

Pre-STW 336.67 (101.5) 1.34 (0.16) 0.21 (0.15) 0.76 (0.17) 2.08 (0.56) 0.46 (0.31) 0.53 (0.16) 63.02 (18.7)

Post-STW 910.22 (268.8) 1.35 (0.14) 0.19 (0.14) 0.73 (0.19) 2.21 (0.47) 0.48 (0.30) 0.58 (0.18) 70.48 (22.8)

P-value .02* 0.93 0.79 0.59 0.40 0.79 0.38 0.20

0

2

4

6

8

10

12

Absolute Claudication Distance

58

60

62

64

66

68

70

72

Peak Plantar Flexor Strength

*

0 6 12 18 24 30 36 42 48 54 60 66 72 78 84 90 96-1

0

1

2

3

Ankle Power Pre and Post STW

Pre-STWPost-STW

% Stance

Watt

s/kg

Figure 2. Mean ensemble curve for ankle power normalized to mass for patients with PAD, Pre (blue) and Post (purple) STW plotted against percent of stance.

(ft/l

bs)

(m)

Torq

ue (N

m/k

g), P

ower

(W/k

g)