Background <p>Sitting up and rising are basic daily activities that can become seriously impaired due to a stroke. This dysfunction can be a reason for limiting the ability to perform other daily activities. The aim of the study was to conduct functional and kinematic estimation of abnormalities of sitting down and getting up in people after a stroke.</p> Methods <p>Twenty-nine patients after stroke (mean age: 52.9 ± 7.8) and 29 healthy volunteers (mean age: 50.9 ± 7.4) were included in this study. The wireless sensors and functional tests, such as the 30-s Chair Stand Test (30CST) and The Five Times Sit-to-Stand Test (FTSST), were used to assess functionally and kinematically of the movement of getting up and sitting down. The force platform was used to assess the symmetry index (SI).</p> Results <p>A significantly higher mean square error (MSE) was observed in the paretic limb compared to the control limb (<i>p</i> = 0.037) during sitting on a chair. A lower average angular velocity of the knee joint of the paretic limb compared to the non-paretic limb (<i>p</i> = 0.027) was observed while getting up from a chair. Stroke survivors needed more time to perform the FTSST test (<i>p</i> &lt; 0.001) and performed fewer repetitions of getting up and sitting down in the 30CST test (<i>p</i> &lt; 0.001) than healthy volunteers. Compared to the control group, more significant limb load asymmetry in the standing position was observed in the study group (<i>p</i> &lt; 0.001).</p> Conclusions <p>The differences detected between stroke patients with hemiparesis and healthy individuals in the results of kinematic and functional tests allow for the direction of lower limb therapy in patients in the early period of post-stroke rehabilitation.</p>