ABSTRACT
Purpose: The present study aimed to determine the effect of dual-tasking on spatiotemporal characteristics in subjects with and without Anterior Cruciate Ligament Deficiency [ACLD] using linear dynamics
Methods: In this mixed model design study, spatiotemporal parameters were measured in 22 patients with ACLD [25.95 +/- 4.69 y] and 22 control subjects [24.32 +/- 3.37 y] while they were walking with different levels of gait velocity [high velocity, self-selected velocity, low velocity] in isolation or concurrently with auditory Stroop task. Coefficient of Variation [CV] was used to calculate variability of step length, step time and step width as dependent variables using custommade MATLAB code. Mixed model of analysis of variance and post hoc analyses were used for data analysis
Results: The results showed that interactions of group by gait velocity due to cognitive difficulty were not significant for all mentioned variables [P>0.05]. Group Interactions due to cognitive task difficulty were significant only in CV of step width [P=0.05]. Interactions of motor task difficulty by cognitive difficulty were significant for CV of step length, step time, and step width in all participants [P<0.05]. The main effects of gait velocity in all dependent variables were significant [P<0.05]
Conclusion: Results showed that step width variability is a more sensitive measure for detecting interaction of group due to cognitive task difficulty compared to variability of step length and step time. Future studies could test this hypothesis in ACL deficient subjects using different measures
ABSTRACT
Objectives: This paper describes further improvement and preliminarily evaluation of a novel viscoelastic ankle-foot prosthesis prototype. The objective was to control the ankle hysteresis at slow and normal walking speeds.
Methods: Inspired by the ankle biomechanics, in which the hysteresis differs based on the gait speeds, a manually damping control mechanism imbedded in the prosthesis for adjusting the ankle damping at slow and normal walking speeds. The prototype was then preliminarily tested on an able-bodied subject wearing an adaptor which simulates the amputee walking. The ankle joint kinetics and kinematics were measured in a gait analysis lab at different walking speeds.
Results: The results suggest that the viscoelastic ankle foot prosthesis prototype could provide a smooth normal-like walking for most of the measured gait characteristics in slow and normal speeds.
Discussion: Therefore, it is suggested to apply a controllable damping mechanism based on the gait speeds in the design of new prosthetic feet.
ABSTRACT
To investigate the friction of rabbit's knee joint with designed pendulum friction tester to diagnose and evaluate different pathological and therapeutic conditions following haemarthrosis, osteoarthritis, and other joint disorders. Friction coefficient of 10 adult male Albino rabbit's joint [5 right and 5 left knees] weighted 1.59 +/- 0.27 Kg, after designing and compiling the instrument and its processing software in the Physiotherapy department of Tarbiat Modares University were measured. Maximaum pendulum rotation, number of oscillations to reach equilibrium, coefficient of friction with Stanton's equation, exponential and linear curve fitting, average logarithmic and linear decrement methods were measured. Maximum rotation after pendulum releasing in the left joints were higher than the right ones, P<0.001.Number of oscillations to reach equilibrium in the left knees were also greater than the right knees, P=0.005.All different friction estimation methods had the same results and showed greater friction in the right in comparison to the left side. The pattern of the joints amplitude decay did not have a linear behaviour and the rabbit's knee joint coefficient of friction with nonlinear estimations was less than linear ones. The findings revealed that selecting a separate control group in such investigation is essential and the contralateral limb could not be considered as control group. Pendulum friction tester has the capability of evaluating changes in coefficient of friction after application of different therapeutic methods. These changes have important role in diagnosis, evaluation of joint diseases and developing techniques for treating those pathologies