ABSTRACT
Objective To document the kinematics of upper-limb motor dysfunction among hemiplegic stroke survivors.Methods Thirty-nine stroke survivors with hemiplegia were selected as the experimental group,while twenty-five healthy counterparts were chosen as the control group.Reaching movements performed in the sagittal plane were divided into an anteflexion phase and a holding phase.Three-dimensional kinematics data were captured using a micro-sensor motion capture system,and surface electromyograms (sEMGs) were recorded synchronously from the upper trapezius (UT),the anterior (AD) and middle (MD) segments of the deltoid,the biceps brachii (BB) and the triceps brachii (TB).The torso twist (TTD),the range of motion (ROM) of the shoulder,movement velocity (MV),isotonic instability degree (IT) and isometric instability degree (IM) were extracted.Integrated electromyography (iEMG) and work ratios were chosen as indicators to compare the two groups.The experimental group's kinematic indicators were correlated with that group's sEMG parameters.Results The average TTD,IT and IM in the experimental group were significantly larger than those of the control group,while the ROM of the shoulder and the MV were significantly smaller.During the anteflexion phase,the average iEMG from the UT in the experimental group was significantly larger than that of the control group,while the average iEMGs from their AD and TB were significantly smaller;The BB/TB work ratios in the experimental group were significantly greater than those of the conrol group,while the AD/UT and AD/MD ratios were significantly smaller.The results during the holding phase were similar.In the experimental group,torso twist was found to be positively correlated with the iEMG of the UT,and the ROM of the shoulder and movement velocity were also positively correlated with the iEMG of the AD.Conclusions Kinematics variables and sEMG features can be used to evaluate the motor dysfunction of hemiplegic stroke patients' affected upper limbs quantitatively and provide guidance for rehabilitation.
ABSTRACT
Objective To analyze the bio-mechanics when hemiplegics reach with the unaffected upper limb.Methods Thirty post-stroke hemiplegics were selected into the patient group,while 23 healthy counterparts were chosen for the control group.Both groups completed a reaching test of their upper limbs which divided reaching into a moving stage and a holding stage.Surface electromyography (sEMG) data were recorded during the tests along with the degree of torso twist,the range of motion of the shoulder,movement velocity,smoothness of movement and angle divergence collected using a wearable micro-sensor motion capture system.Results For the stroke patients whose dominant upper limb was unaffected,the average root mean square (RMS) signal from the upper trapezius (34.3 μV) and the average torso twist (-1.4°) in the moving phase were significantly larger than among the control subjects (19.7 μV and-2.3°),but their average movement velocity was significantly slower.In the holding phase the average RMS signal from the upper trapezius (55.4 μV) was still significantly higher than in the control group,but their average pectoralis major signal and the integrated EMG ratio of the anterior segments of the deltoid and upper trapezius muscle pairs were significantly lower.For the stroke patients whose dominant upper limbs were affected,in thc moving phase their average signal from the middle segments of the deltoid were significantly greater than those of the controls,but their movement velocity was significantly slower.For the control subjects,in the moving phase the average signal from the upper trapezius on their non-dominant side was significantly higher than that from the dominant upper limb.The integrated EMG ratio from the anterior segments of the deltoid and upper trapezius muscle pairs on that side was smaller throughout the whole reaching movement.Conclusion The bio-mechanical characteristics in reaching of the unaffected upper limbs of stroke patients are not the same as those of the corresponding upper limbs of healthy subjects.It is more reasonable to select the corresponding upper limbs of healthy subjects as controls when a bio-mechanical study of the affected upper limbs is conducted.