Supervised Walking Exercise Therapy Improves Gait Biomechanics in
Supervised Walking Exercise Therapy Improves Gait Biomechanics in Patients with Peripheral Artery Disease Molly Schiebera, Iraklis I. Pipinosc, d, Jason M. Johanningc, d, Holly K. De. Spiegelaere, Benjamin Senderling, Cassidy Berlina, b, Sara A. Myersa, b a. Department of Biomechanics, University of Nebraska at Omaha, Nebraska c. Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska b. Department of Surgery, Veterans Affairs Medical Center of Nebraska and Western Iowa, Omaha, Nebraska INTRODUCTION RESULTS v Peripheral artery disease (PAD) is a prevalent vascular disease where atherosclerotic blockages restrict blood flow to the lower extremities 1, 2 v Intermittent claudication is the most common presentation of PAD, where metabolic demands of the lower limbs exceed the limited supply of blood, causing ischemia and altered gait. Healthy Muscle v Supervised exercise therapy (SET) is the first line of treatment and it increases maximum walking distances in patients with PAD comparable to surgical revascularization therapy, despite the fact that blockages remain. PAD Muscle v Little is known about gait biomechanics following SET. Purpose: To characterize the effects of a SET intervention on gait biomechanics and walking distances in claudicating PAD patients. We hypothesized that SET would improve walking distances in association with gait biomechanics. Joint Moments (N*m) Key: -0. 2 1. 0 -0. 2 -0. 3 0. 5 -0. 2 -0. 4 0. 0 -0. 3 Knee Extensor 0. 8 0. 2 Post-therapy, pain 0. 0 Pain-free Ground Reaction Forces (BW) 1. 3 Impact(V) -0. 10 -0. 15 v 47 patients (age: 69. 2± 7. 0; height (m): 1. 75± 0. 7) with PAD underwent gait analysis before and immediately following SET (Table 1). • 1. Gardner Max Walk Test Gait • 2. Pain-free Overground trials Analysis (pre • 3. Six Minute Walk Test therapy) • 4. Pain-Induced Overground trials -0. 20 Pain-free Pain W/kg: 1. 0 0. 4 0. 0 1. 0 Pain-free Pain Midstance(V) 0. 9 1. 1 Pain-free Pain Propulsive (AP) 0. 5 Pain-free -0. 01 0. 20 -0. 02 Pain-free -0. 04 0. 05 Pre-therapy, pain-free Pre-therapy, pain Post-therapy, pain-free Post-therapy, pain Pain-free Pain Hip Flexor -0. 8 1. 3 Pushoff(V) Pain 0. 5 Pain-free Pain Medial(ML) 0. 08 0. 07 -0. 03 0. 10 0. 00 Pain Lateral (ML) 0. 25 0. 15 Pain 0. 7 0. 6 0. 5 Pain-free 0. 9 0. 7 Pain 1. 1 0. 8 0. 9 Pain-free -0. 6 0. 2 Pain -0. 2 Knee Flexor -0. 4 0. 6 Pain-free Ensemble Ankle Powers During Stance Key: Hip Extensor 0. 8 Pre-therapy, pain -0. 05 -0. 1 0. 4 Braking (AP) 2. 0 1. 5 Post-therapy, pain-free V: Vertical AP: Anterior-Posterior ML: Mediolateral Pain Ankle Plantarflexor -0. 1 Pre-therapy, pain-free METHODS Supervised Exercise Therapy Significant effect of condition, p<0. 05 Significant effect of intervention, p<0. 05 Pain-free 0. 6 Figure 1: Chronic lower limb ischemia and ischemia-reperfusion introduce muscle myopathy 1, 2 , in which dysfunctional mitochondria bioenergetics, oxidative damage, and fiber type shifting are involved. • 24 weeks (3 x per week; 72 total sessions) • 5 minute warmup • 50 minutes of intermittent treadmill walking • 5 minute cool down 0. 0 Ankle Dorsiflexor Pain -0. 05 0. 06 0. 05 Pain-free Pain Ensemble Hip Powers During Stance Key: A 1, H 1: Weight-acceptance phase A 2, H 2: Single-leg support phase A 3, H 3: Propulsion phase Gait Analysis (post-therapy) • Same as pre-therapy evaluation Stance % v Joint kinetics and kinematics were calculated for the sagittal plane during the Stance % stance phase of walking in pain-free and pain conditions. DISCUSSION v Statistical Analysis: paired t-test evaluated walking distances and a twofactor, intervention (pre/post) and condition (pain free/pain), repeated v Weakness in the posterior compartment muscles of the leg characterize the measures ANOVA evaluated gait dependent variables (p<0. 05). underlying gait adaptations patients with PAD demonstrate pre-therapy. v Following SET, patients demonstrated increased torque development by the Table 1. Subject demographics and walking distances hip extensors during weight acceptance, an increase in magnitude in the Dependent Variable Pre Post P lateral ground reaction force, an increase in ankle power absorption during Mass (kg) 89. 38 ± 18. 7 88. 99 ± 18. 9 0. 46 single-leg support, increases in the hip flexors and ankle plantar flexors Ankle Brachial Index 0. 56 ± 0. 17 0. 52 ± 0. 22 0. 078 during propulsion and increased initial and absolute claudication distances. Initial Claudication (m) 99. 20 ± 74. 5 272. 73 ± 249. 3 <0. 001 v Limb function is partially restored despite persistent blockages in the arterial Absolute Claudication (m) 317. 23 ± 230. 8 668. 22 ± 566. 4 <0. 001 tree. Six Minute Walk Distance (m) 340. 42 ± 117. 3 333. 11 ± 123. 3 0. 70 CONCLUSIONS Hip Knee Ankle Table 2. Joint Angles at the Ankle, Knee, and Hip (Pi: intervention; Pc: condition). v Six months (72 sessions) of SET produces significant increases in the Joint Angles PAD Pain Free PAD PAIN treadmill walking distances of patients with claudication that are associated with concurrent improvements in gait biomechanics at the level of the ankle Pre Post Pi Pc and hip. Strengthening of the hip and foot flexor muscles appear to be the Dorsiflexion 12. 86(4. 7) 13. 20(4. 7) 14. 09(4. 7) 14. 11(4. 9) 0. 68 <0. 001 Plantarflexion -7. 34(4. 6) -7. 38(4. 7) -7. 95(4. 5) -8. 31(4. 4) 0. 74 <0. 001 Extension 2. 79(5. 0) 2. 27(5. 1) 2. 24(5. 1) 1. 43(5. 5) 0. 27 0. 003 Flexion 14. 38(5. 7) 14. 14(6. 5) 14. 29(5. 6) 13. 81(6. 8) 0. 57 0. 476 Extension -2. 80(4. 9) -3. 86(5. 8) -1. 90(5. 2) -2. 97(6. 0) 0. 28 <0. 001 Flexion 34. 04(6. 2) 34. 12(7. 0) 34. 54(6. 9) 34. 55(7. 5) 0. 95 0. 055 Support for this work was provided by funds from the NIH (R 01 AG 034995, R 01 HD 090333, and P 20 GM 109090), the VA RR&D (1 I 01 RX 000604), and the National Aeronautics and Space Administration (NASA) Nebraska Space Grant. main mechanisms producing improvements in walking distances. v Future work should aim to identify which patients will and will not respond to SET REFERENCES 1. Pipinos II et al. Vasc & Endo Surg. 2008; 42(2). 3. Koutakis P, et al. J of Vasc Surg. 2010; 51(1). 2. Pipinos II et al. Vasc & Endo Surg. 2008; 41(2). 4. Koutakis P, et al. J of Vasc Surg. 2010; 52(2).
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