Observations on the kinematic characteristics of the healthy side of the knee in stroke patients: A cross-sectional study

The abnormal gait of stroke patients not only severely limits the recovery of their walking ability, but also seriously affects their quality of daily life. Previous observational studies have focused too much on the observation of single degree of freedom and axial knee motion angles in stroke patients. Changes in the multi-degree of freedom and multi-axial joint angles of the knee have been less frequently observed, leading to somewhat limited conclusions. Therefore, the aim of this study was to use the Opti-knee motion test to analyze in real time the motion of the knee in all directions on the healthy side of stroke patients and to compare it with normal gait to provide a clinical basis for subsequent rehabilitation. In a cross-sectional study, 120 subjects (60 stroke patients were as the observation group and 60 healthy subjects as the control group) were studied. Both groups of subjects were tested for Opti-Knee tri-axial angles of motion of the healthy side of the knee, including flexion and extension, internal and external rotation, internal and external turning, anterior and posterior displacement, superior and inferior displacement, left and right displacement, maximum extension angle and maximum flexion angle. Compared with the control group, there were significant changes in the joint angles of flexion and extension, internal and external rotation, internal and external turning, maximum extension and maximum flexion of the knee on the healthy side in the observation group, and the differences were statistically significant [95%(37.22, 45.13), P = .01], [95%(9.51,13.67), P = .018], [95%(4.82,7.57), P = .049], [95%(4.12, 8.63), P = .019], [95%(51.68, 57.28), P = .0001]. However, there was no significant change in the angle of motion of the healthy side of the knee for anterior-posterior displacement, superior-inferior displacement and internal-external displacement in either group and the differences were not statistically significant [95%(1.16, 1.78), P = .72], [95%(0.85,1.32), P = .32], [95%(0.57, 0.88), P = .36]. This study confirms the importance of changes in the angle of motion of the knee on the side of the stroke patient in maintaining the stability of the knee joint. Therefore, their bilateral lower limb symmetry training should be paid attention to in the subsequent rehabilitation treatment.