Question

When reporting gait and/or kinematics data, authors report a continuous graph of the average and standard deviation. Research how this type of graph is created and write up a tutorial on how to create these types of graphs

Answer 1

Gait is basically defined as the general mannerism of walking. Human gait is analysed by normalizing and averaging the data collected from series of isolated and independent strides. Gait analysis is very effective in finding out the effective solution and medical treatment of severe diseases like cerebral palsy. Gait analysis involves the data collection based on 3 D motion capture methods. It tracks the 3 D position of the specific points placed on the body of person.

The main variable obtained from the gait analysis basically involves joint’s angles, power and joint moment attached to the joints. It also measures the forces or ground reaction from the plates attached to the person feet.

Tutorial:

1. The health history of subjects (male or female) are noted so as to rule out any history of medications, illnesses, surgeries, or other injuries that may have affected their gait.
2. A self-contained application or data logger can be used to collect the kinematic data during walking.
3. Start and end times for walking stride are defined in correspond to maximum knee extension just prior to heel strike.
4. Average walking speeds and stride lengths are calculated by :

= Total distance walked (in specified time)/Total number of strides.

5. Standard deviations of stride times and average stride times can be calculated from the individual stride times obtained from the continuous time series data.

6.Data collected from each stride are time-normalized with respect to samples.

7.These re-sampled data are plotted across strides to compute stride-to-stride standard deviations.