50 female fibromyalgia patients

50 pain-free female volunteers

Posture analysis will be evaluated by DIERS Formetric 4D (Diers International GmbH, Schlangenbad, Germany). Participants will be positioned two meters away from the projector. The slide projector projects a series of parallel light strips on the back of the participant. The back's surface will be captured on camera converted to digital data, and displayed in three dimensions. Every scan will record 12 images over 6 seconds (2Hz) and the manufacturer's recommendations will be followed for processing.

Spinal reference points, measures of the spinal curves, distance and localization, imbalances of the trunk and pelvis and spinal deviation will be measured. Spine parameters are expressed in millimeters, percentages or degrees depending on the specific parameter.

The static and dynamic postural control will be measured by HUR SmartBalance BTG4 system (Hur Labs, Tampere, Finland). Participants will be asked to stand barefoot on the balance platform and to stand as quietly as possible, looking forward, during the measurement. While the stable surface is the platform's own floor, the unstable surface is the foam cushion provided by the manufacturer with the device. Data will be collected for 30 seconds. The following parameters will be calculated from the center of pressure (CoP) displacement time series for static postural control: sway area, velocity, Romberg. The limits of stability (LOS) was used to evaluate the dynamic postural control. The participants were asked to tilt their bodies forward, backward, leftward, and rightward for 8 seconds in each direction on the same platform.

Spatio-temporal gait analysis was performed by Zebris FDM type 3 (Zebris Medical GmbH, Germany) gait analysis system. The system consists of a 3 meters long main platform which contains sensors for measuring the force distributions and a 1 meters long maneuvering platforms that located at the beginning and end of the main platform. Participants will be asked to walk barefoot on the platform. Each participant will walk at their comfortable speed for 2 minutes continuously going from one end to the other along a 5-m walkway in a quiet, well-lit room. The main platform was located in the middle of the system in order to avoid the unstable walking periods on turns. The data were analyzed and recorded on the computer. Foot rotation, stride length, step width, double limb support phase, cadance will be measured. Gait parameters are expressed in centimeters, percentages or degrees depending on the specific parameter.

In FM group; Fibromyalgia Impact Questionnaire (FIQ) will be used to measure the impact of FM on patient's physical function, health status and the severity of disease activity. FIQ is scored from 0-100. Higher scores indicate increased severity of the impact of FM.