Fatigability Assessment Using the Fatigue Index Kliniken Schmieder (FKS) Is Not Compromised by Depression

Abstract

Background: Attractor-based kinematic gait analysis using the Fatigue Index Kliniken Schmieder (FKS), have been suggested as a sensitive tool to determine motor fatigability in persons with Multiple Sclerosis (pwMS). Hypothesis: Depression does not affect the FKS to a similar degree as in pwMS. Methods: We recruited 32 patients with major depression. Data were collected with two accelerometers attached to both ankles. Data were recorded for one minute at the beginning and at the end of the treadmill test. Attractor attributes were used to analyze the data. Results: The mean Fatigue Index Kliniken Schmieder (FKS) was 2.1. The change of the attractor ( δM ) was 3.7 and the change of variability ( δD ) was 0.6. Mean values were clearly below values of pwMS with fatigability from a previous publication. However, the individual level values from six individuals—five of them showed pain related comorbidity besides depression—fell within the lower pathological range. There was no correlation between Hamilton depression scale and the attractor attributes ( δM and δD ). Discussion: Depression does not affect gait as motor fatigability does in pwMS. Results from subjects with pain during the treadmill test show a moderately increased variability and moderately altered attractors.