Narrow Results

Recognizing individuals by their gait is a new biometric methodology, which employs dynamic features derived from tracking gait. Instead of the image processing techniques used in most existing studies, our previous study initialized the work of investigating gait recognition in terms of biomechanics. The experimental results showed that the angles and forces of the lower limb joints were reliable features for recognition of individuals, which can provide us with a considerable amount of information in the field of computer science and thus help in developing a more efficient recognition method, which is also more computationally efficient than current image processing methods. Encouraged by the early results, in this study, we proposed a people recognition method based on plantar pressure patterns, which can be used in a concealed manner. We hoped to prove the feasibility of using foot pressure for individual recognition.

Two different plantar pressure parameter measurement schemes are discussed: (1) the characteristic parameters and (2) the pressure values of each sensor cell in each frame. The self-organizing map (SOM) neuron network algorithm was used in both schemes for data classification. In order to improve the recognition rate, a support vector machine (SVM) was used as the data classification algorithm for the all-sensor-values method. High recognition rates were achieved with the second method, i.e., using all the sensor cell values of the foot pressure pattern during walking, regardless of the algorithm used. It is suggested that the foot pressure distribution of gait is a suitable feature for gait recognition. Both SOM and SVM can be feasible classifiers for foot pressure-based features.

Arthroscopic cartilage regeneration facilitating procedure (ACRFP) has been reported with satisfactory results, yet there is limited research on the biomechanics in these patients. The purpose of this study is to assess the change on the biomechanics after ACRFP, in terms of foot pressure and gait pattern. Patients with chronic knee pain due to osteoarthritis and received ACRFP were recruited, and the knee joints in each patient were divided into either study or control group according to radiographical or symptomatic severity. Assessments were done with Knee injury and Osteoarthritis Outcome Score (KOOS) and dynamic foot pressure at the time before surgery, three months and six months postoperatively. A total of 24 patients completed the study. Significant improvement was found of KOOS, at both three and six months postoperatively. No much change in the gait parameters was noted, but there was a significant decrease of foot pressure over lateral side of hindfoot at six months postoperatively. In conclusion, significant clinical improvements could be achieved with surgical results of ACRFP, and shifting of the foot pressure medially may be related to decrease in the knee adduction moment, which is more favorable for the knee joints.

Plantar pressure refers to the interfacial contact pressure between the foot and the supporting surface during daily locomotor activities. Information derived from plantar pressure measures is essential in gait and posture research for diagnosing patho-mechanics associated with the musculoskeletal diseases. In particular, it is compulsory to reduce the abnormally high plantar pressure in people with diabetes for the prevention and treatment of foot ulcerations in this population. In this study, a portable biofeedback-based gait training device is developed to advocate able-bodied subjects to adopt different movement patterns in walking to manipulate the plantar pressure distribution under the foot. Through the simultaneous detection of the plantar pressure pattern and the kinematics of the lower extremity joints, it was revealed that the unloading effects for the plantar site in particular to the lateral forefoot subareas were more abundant through biofeedback-assisted gait alterations than the self-awareness control for gait adjustment. In addition, the corresponding relationship between joint coordination and pressure redistribution pattern was obtained, which could potentially be used in gait retraining interventions to correct abnormal plantar pressure patterns in people with diabetes.

The aim of this paper is to investigate the effect of prolonged running on lower limb muscle activity, foot pressure and foot contact area. The treadmill running test was performed at a running velocity of 12 km/h for 20 minutes. Twenty-nine male students from the Army Infantry School took part in this study. For all subjects in our study, a number of variables were analyzed by the prolonged running. The EMG variables included the signal maximum amplitude of EMG linear envelope of all the muscles. Meanwhile, maximal forces and peak foot pressures in 10 anatomically defined areas of the foot, and contact area of the whole foot were analyzed. Running EMG data in each of the phases (phase 2–4) were compared to those at the beginning of the run (phase 1). Dynamic pedography data in phase 4 was compared to those of phase 1. Pedography analysis revealed a significant increase in the maximal forces and peak pressures under the medial midfoot and all forefoot regions. From phase 1 to phase 4, the maximal force increased by 32% under the medial midfoot, 29% under the first metatarsal, 34% under the second and third metatarsal, and 21% under the fourth and fifth metatarsal. The peak pressure under the medial midfoot increased by 19%, under the first metatarsal increased by 21%, under the second and third metatarsal increased by 31%, and under the fourth and fifth metatarsal increased by 21%. The averaged maximum EMG amplitudes of almost all the muscles were increased gradually as time increased. Among them, rectus femoris, gastrocnemius, soleus, and tibialis anterior muscles reach a significant amplitude at the p < 0.05 level. In conclusion, our results showed that a prolonged running under a 20 minutes limitation led to a greater increase in muscle amplitude, midfoot and forefoot loading compared with the beginning of running.