Floor Gait Analysis

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2.2 Floor Sensors In floor sensor technique, sensors are place along the floor known as force platform or instrumented walkways where gait is measured by pressure or force sensors and moment transducers when the subject walks on them. There are two types of floor sensors which are force platforms and pressure measurement systems. Force platforms should be distinguished from pressure measurement systems which, although they too quantify the centre of pressure, do not directly measure the force vector applied. Pressure measurement systems are useful for quantifying the pressure patterns under a foot over time but cannot quantify horizontal or shear components of the applied forces. An example of an instrumented floor sensor and the acquired…show more content…
This type of system is used in many gait analysis studies [3]. 2.3 Wearable Sensors In gait analysis using wearable sensors, these are placed on various parts of the patient’s body, such as the feet, knees or hips to measure different characteristics of the human gait. This is described in several recent reviews. This section offers a brief overview of the different types of sensors which are most commonly used in research [6-8]. They include force sensors, accelerometers, gyroscopes, extensometers, inclinometers, goniometers, active markers, and electromyography. 2.3.1 Pressure and Force Sensors Force sensors measure the Ground Reaction Force (GRF) under the foot and return a current or voltage proportional to the pressure measured [7]. Pressure sensors, however, measure the force applied on the sensor without taking into account the components of this force on all the axes. The most widely used models of this type are capacitive, resistive piezoelectric and piezoresistive sensors. The choice of sensor depends on the range of pressure it will stand, linearity, sensitivity and the range of pressure it…show more content…
During walking, there are several events and phases involved in completing the one gait cycle. Figure 2.4.1 below shows the position of legs during walking. Figure 2.4.1: Position of legs for one complete gait cycle The gait cycle is the period between the initial contact of one foot with the ground and its next contact with the ground. The timing of events occurring during a gait cycle is usually described as a percentage of this cycle, considering the initial contact as 0% and the second contact of the same foot as 100%. The gait cycle is divided into stance phase and swing phase. Stance occupies approximately 60% of the cycle and swing the remaining 40% [7]. Human gait characteristics depend on age, anatomical or structural characteristics, and walking speed. Each individual has a preferred or self-selected speed, which is optimal for energy conservation. Deviations from this optimal speed alter gait characteristics. When considering pathological gait, the variability of normal gait patterns should be taken into account. Some perceived gait abnormalities may be normal variants or compensations for other underlying

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