Gait variability is altered in patients with peripheral arterial disease

Abstract

Symptomatic PAD patients have increased gait variability at the ankle, knee, and hip joints at baseline ambulation in the absence of claudication pain. Our findings indicate significant baseline deterioration in the locomotor system of symptomatic PAD patients. This deterioration results in increased noise and instability of gait and is a potential contributing factor to the falls and mobility problems experienced by symptomatic PAD patients.

Prosthesis preference is related to stride-to-stride fluctuations at the prosthetic ankle

“…Lower-limb joint angle flexion/ extension time series for each joint covering the duration of the entire 3 min were then calculated from the raw marker position data using custom MATLAB software (MathWorks Inc; Natick, Massachusetts). This time frame was deemed sufficient to properly characterize the walking dynamics based on previous work [18,[21][22]26] and is considerably longer than the approximately 7 strides found adequate by Sloot et al [27].…”

“…The LyE was chosen because it is ideal for inherently quasi-periodic signals (i.e., limit cycle) [21][22]. Joint kinematic patterns are inherently quasiperiodic.…”

“…The LyE measures the exponential divergence of the movement trajectories within the reconstructed state space (Figure 2) [14,[28][29][30]. State space reconstruction is a nonlinear dynamics technique that uses a time delay (τ) to create M copies of the original time series, where M is the embedding dimension ( Figure 3) [21,[28][29].…”

“…Therefore, the purpose of this study was to quantify the stride-to-stride fluctuations through the LyE during gait for patients with a lower-limb amputation walking in two separate prosthesis setups. The LyE has been used in the gait literature to quantify changes in these fluctuations [17][18][19][20][21]. The LyE was chosen (as opposed to other metrics such as detrended fluctuation analysis or sample entropy) specifically for its distinct benefits of measuring divergence of cycles within the attractor, making it ideal for investigating variability in joint kinematic patterns, which are inherently periodic [21][22].…”

“…The LyE has been used in the gait literature to quantify changes in these fluctuations [17][18][19][20][21]. The LyE was chosen (as opposed to other metrics such as detrended fluctuation analysis or sample entropy) specifically for its distinct benefits of measuring divergence of cycles within the attractor, making it ideal for investigating variability in joint kinematic patterns, which are inherently periodic [21][22]. This inherent periodicity can largely influence other metrics and dominate their outcomes when we are truly interested in the fluctuations that exist on top of these intercycle periodic dynamics.…”