Movement Coordination Of Trunk And Extremities And Its Mechanism During Walking In Patients With Ankylosing Spondylitis

Objectives:To investigate the effects of Pathological changes in Ankylosing spondylitis (AS) onchanges in all segments Transverse Rotational Amplitude （TRA）， RelativeFourier Phase（RFP）and its possible mechanism when speeding up walking and/orincreasing length walking.Methods:Twelve healthy male subjects walked on a treadmill at1.0k m/h、2.0k m/h、3.0k m/h、4.0k m/h、5.0k m/h, with normal, or large steps, making for a total of10conditions. Markers for OPTOTRAK registration were attached at the level of thethorax, the pelvis, spine、upper leg and foot of each subject. Subjects’ movementswill be filmed with an OPTOTRAK camera during each condition. Segmental RFPand TRA were calculated via Mat lab R2007a.SPSS20.0software was used to analyse the difference between AS and Controlon age、weight、height and BMI with unpaired t test。Repeated measures ANOVAswas performed on stride length, stride frequency、step width、RFP and TRA.Results:1.Basic Gait CharacteristicMean step widths in AS group are smaller than that in control group whenwalking on treadmill at most conditions(p=0.04).Increasing velocity led to smallerstep width(p=0.000). No significant difference in stride length or frequency between two groups was observed (P>0.05).2.TRAThorax TRA in AS group are lower than that in control group(p=0.007).TheThorax TRA decreased with speed at all velocity(p=0.000).Spine TRA in AS group are lower than that in control group(p=0.006).Thespinal amplitudes increased with speed at all velocity(p=0.000) as well as steplength(p=0.001).Pelvic TRA in AS group are lower than that in control group(p=0.043).ThePelvic amplitudes increased with step length(p=0.000). the overall effects at speed onpelvic TRA present graphically in a U-form.3. Relative Fourier Phases (RFP)Thorax-pelvic RFP decreased gradually with the increase of step length(p=0.028). The RFP increased during speeding up walking at treadmill (p=0.000).Pelvic-leg RFP decreased gradually with the increase of step length (p=0.001).The RFP decreased during speeding up walking at treadmill(p=0.000).With increase of step length, the thorax-leg RFP decreased gradually(p=0.000).Conclusions:1.The effects of pathological changes in Ankylosing spondylitis (AS) led todecrease of TRA compared with healthy controls. As a consequence, it may causethe results that mutual rotation between segments was suppressed.2.Ankylosing spondylitis walk with small step width to reduce the risk of fallingbecause of pathological changes in AS.3.To deal with the pathological changes in AS during walking, the AS patientsmay change the selected strategy, which is suppressed by many interactions.Therefore, to seek walking strategies and negative influence in AS at different conditions,this paper will provide beneficial idea for the clinical diagnosis andtreatments of progressive disease.