Foot drop Common Causes. Introduction: This information shows the various causes of Foot drop, and how common these diseases or conditions are in the general population. This is not a direct indication as to how commonly these diseases are the actual cause of Foot drop, but gives a relative idea as to how frequent these diseases are seen overall.
Variability refers to how spread out a group of data is. The common measures of variability are the range, IQR, variance, and standard deviation. Measures of variability are descriptive statistics, which means they can only be used to describe the study data.
The IQR is a measure of variability, based on dividing a data set into quartiles. Quartiles divide a rank-ordered data set into four equal parts. The values that separate parts are called the first, second, and third quartiles; and they are denoted by Q1, Q2, and Q3, respectively.