The metadata file contains annotations and additional subject-related information. It is structured as a matrix with N rows x M columns. Here, the first two columns hold the SUBJECT_ID and SESSION_ID, the other columns hold information such as class labels, sex, body mass, age, shod-condition, etc.. Note that this information is available in all records. Missing values are identified as „NaN“. A particularly notable field is AFFECTED_SIDE, which indicates which leg is affected by a certain impairment (e.g. left knee) or if both sides are affected.