The effect of pharmacological treatment on gait biomechanics in peripheral arterial disease patients

<p>Abstract</p> <p>Background</p> <p>Pharmacological treatment has been advocated as a first line therapy for Peripheral Arterial Disease (PAD) patients suffering from intermittent claudication. Previous studies document the ability of pharmacological treatment to increase walking distances. However, the effect of pharmacological treatment on gait biomechanics in PAD patients has not been objectively evaluated as is common with other gait abnormalities.</p> <p>Methods</p> <p>Sixteen patients were prescribed an FDA approved drug (Pentoxifylline or Cilostazol) for the treatment of symptomatic PAD. Patients underwent baseline gait testing prior to medication use which consisted of acquisition of ground reaction forces and kinematics while walking in a pain free state. After three months of treatment, patients underwent repeat gait testing.</p> <p>Results</p> <p>Patients with symptomatic PAD had significant gait abnormalities at baseline during pain free walking as compared to healthy controls. However, pharmacological treatment did not produce any identifiable alterations on the biomechanics of gait of the PAD patients as revealed by the statistical comparisons performed between pre and post-treatment and between post-treatment and the healthy controls.</p> <p>Conclusions</p> <p>Pharmacological treatment did not result in statistically significant improvements in the gait biomechanics of patients with symptomatic PAD. Future studies will need to further explore different cohorts of patients that have shown to improve significantly their claudication distances and/or their muscle fiber morphology with the use of pharmacological treatment and determine if this is associated with an improvement in gait biomechanics. Using these methods we may distinguish the patients who benefit from pharmacotherapy and those who do not.</p

Gait kinematics and kinetics are affected more by peripheral arterial disease than by age

—Peripheral arterial disease (PAD) produces abnormal gait and disproportionately affects older individuals. The current study investigated PAD gait biomechanics in younger (\u3c65 yr) and older (\u3e/=65 yr) subjects. The study included 61 patients with PAD (31 younger, age: 57.4 +/– 5.3 yr, and 30 older, age: 71.9 +/– 5.2 yr) and 52 nondisabled age-matched control subjects. Patients with PAD were tested during pain-free walking and compared with control subjects. Joint kinematics and kinetics (torques) were compared using a 2 x 2 analysis of variance (groups: patients with PAD vs control subjects, age: younger vs older). Patients with PAD had significantly increased ankle and decreased hip range of motion during the stance phase as well as decreased ankle dorsiflexor torque compared with control subjects. Gait changes in older individuals are largely constrained to time-distance parameters. Joint kinematics and kinetics are significantly altered in patients with PAD during pain-free walking. Symptomatic PAD produces a consistent ambulatory deficit across ages definable by advanced biomechanical analysis. The most important finding of the current study is that gait, in the absence of PAD and other ambulatory comorbidities, does not decline significantly with age based on advanced biomechanical analysis. Therefore, previous studies must be examined in the context of patients with potential PAD being present in the population, and future ambulatory studies must include PAD as a confounding factor when assessing the gait function of elderly individuals

The effect of exoskeleton footwear on joint angular motion during walking in patients with peripheral artery disease

Gait, Lower Extremity, Peripheral Artery Disease, Joint Angle, Exoskeleton Footwear, Exoskeleton, Assistive Device, Walking

Peripheral Arterial Disease Affects the Frequency Response of Ground Reaction Forces During Walking

Background—Walking is problematic for patients with Peripheral Arterial Disease. The purpose of this study was to investigate the frequency domain of the ground reaction forces during walking to further elucidate the ambulatory impairment of these patients. Methods—Nineteen bilateral peripheral arterial disease patients and nineteen controls were included in this study. Subjects were matched for age and gait speed. Participants walked over a force plate sampling at 600Hz. PAD patients were tested before (pain-free condition) after the onset of claudication symptoms (pain). We calculated median frequency, frequency bandwidth, and frequency containing 99.5% of the signal for the vertical and anterior-posterior ground reaction forces. Findings—Our results showed reduced median frequency in the vertical and anterior-posterior components of the ground reaction forces between the control group and both peripheral arterial disease conditions. We found reduced frequency bandwidth in the anterior-posterior direction between controls and the peripheral arterial disease pain-free condition. There were no differences in median frequency or bandwidth between peripheral arterial disease pain-free and pain conditions, but an increase in the frequency content for 99.5% of the signal was observed in the pain condition. Interpretation—Reduced frequency phenomena during gait in peripheral arterial disease patients compared to velocity-matched controls suggests more sluggish activity within the neuromotor system. Increased frequency phenomena due to pain in these patients suggests a more erratic application of propulsive forces when walking. Frequency domain analysis thus offers new insights into the gait impairments associated with this patient population

Preoperative frailty predicts postoperative complications and mortality in urology patients

Purpose Our objective was to determine the impact of preoperative frailty, as measured by validated Risk Analysis Index (RAI), on the occurrence of postoperative complications after urologic surgeries in a national database comprised of diverse practice groups and cases. Study design The National Surgical Quality Improvement Program (NSQIP) database was queried from 2005 to 2011 for a list of abdominal, vaginal, transurethral and scrotal urological surgeries using Current Procedural Terminology codes. The study population was subdivided into two groups based on the nature of procedures performed: complex procedures (inpatient) and simple procedures (outpatient). Risk Analysis Index score was calculated using preoperative NSQIP variables to determine preoperative frailty. Major postoperative morbidities (pulmonary, cardiovascular, renal and infectious), mortality, return to operating room, discharge destination and readmission to the hospital were examined. Results The study identified 42,715 patients who underwent urological procedures, 25,693 complex and 17,022 simple procedures. Mean RAI score (range) was 7.75 (0–53). The majority of patients scored low on the RAI (90.57 % with RAI \u3c 10). As the RAI score increased, there was a significant increase in postoperative complication and mortality rate (both p \u3c 0.0001). Similarly, the rate of return to operating room and hospital readmission rate increased as RAI increased (both p \u3c 0.0001). Additionally, rate of discharge to home decreased. Interestingly, mortality rate in patients with high RAI did not differ comparing simple to complex procedures (p = 0.90), whereas complications were significantly greater in the complex operation (p = 0.01). Conclusions Increase in frailty, as measured by RAI score, is associated with increased postoperative complications and mortality. RAI may allow for rapid identification and counseling of patients who are at high risk of adverse perioperative outcomes

Changes in ankle muscle force and power during walking in patients with peripheral artery disease

Background: Patients with peripheral artery disease (PAD) have significantly reduced lower extremity muscle strength compared with healthy individuals as measured during isolated, single plane joint motion by isometric and isokinetic strength dynamometers. The objective of this study was to understand the contribution of the ankle muscles during walking in patients with PAD and compared to healthy older individuals. Methods: A total of 12 patients diagnosed with Fontaine stage II PAD and 10 healthy older controls were recruited for the study. Each subject walked across a 10-meter pathway with reflective markers placed on specific anatomical locations on lower limbs while the marker coordinates were recorded using a 12-high speed infrared camera system. Gait simulations were performed in OpenSim software (version 4.0). The muscle force and power for individual muscles at ankle and as a group of ankle plantar flexor muscles were exported from OpenSim. Results: There was a significant reduction in ankle muscle power in patients with PAD during propulsion phase (p \u3c 0.05). There were significant reductions in lateral and medial gastrocnemius muscle forces and power during propulsion in patients with PAD (p \u3c 0.05). However, soleus muscle force and power were not altered during stance phase. Conclusions: Our simulation findings identified important information about PAD gait mechanics, specifically altered ankle muscle force and power contribution during stance phase