Sit-to-stand is an indispensable functional activity in human daily life, which requires high muscle strength, not only to control the lower limbs, but also to ensure the stable ascension of the trunk. This paper describes in detail the trajectory and speed of the joints through the human sit-to-stand test, analyzes the change rule of the angle of the joints, the angular velocity and the position of the center of mass in the human sit-to-stand, and records in detail the change of the plantar pressure of the subjects in this process. Through the study on joint motion and plantar pressure changes in the process of sit-to-stand, this paper summarizes the kinematics of human body in this process, aiming to provide a basis through the results of this paper for the design of human sit-to-stand assistive devices, which may be used in the future to analyze the sit-to-stand state of patients with lower limb disorders, and carry out the corresponding treatment and rehabilitation training.
Humans ; Biomechanical Phenomena ; Foot/physiology* ; Pressure ; Standing Position ; Adult ; Posture/physiology* ; Movement/physiology* ; Sitting Position

OBJECTIVE: To analyze the disease spectrums underlying orthostatic intolerance (OI) and sitting intolerance (SI) in Chinese children, and to understand the clinical empirical treatment options. METHODS: The medical records including history, physical examination, laboratory examination, and imagological examination of children were retrospectively studied in Peking University First Hospital from 2012 to 2021. All the children who met the diagnostic criteria of OI and SI were enrolled in the study. The disease spectrums underlying OI and SI and treatment options during the last 10 years were analyzed. RESULTS: A total of 2 110 cases of OI and SI patients were collected in the last 10 years, including 943 males (44.69%) and 1 167 females (55.31%) aged 4－18 years, with an average of (11.34±2.84) years. The overall case number was in an increasing trend over the year. In the OI spectrum, postural tachycardia syndrome (POTS) accounted for 826 cases (39.15%), followed by vasovagal syncope (VVS) (634 cases, 30.05%). The highest proportion of SI spectrum was sitting tachycardia (STS) (8 cases, 0.38%), followed by sitting hypertension (SHT) (2 cases, 0.09%). The most common comorbidity of OI and SI was POTS coexisting with STS (36 cases, 1.71%). The highest proportion of treatment options was autonomic nerve function exercise (757 cases, 35.88%), followed by oral rehydration salts (ORS) (687 cases, 32.56%), metoprolol (307 cases, 14.55%), midodrine (142 cases, 6.73%), ORS plus metoprolol (138 cases, 6.54%), and ORS plus midodrine (79 cases, 3.74%). The patients with POTS coexisting with VVS were more likely to receive pharmacological intervention than the patients with POTS and the patients with VVS (41.95% vs. 30.51% vs. 28.08%, χ²= 20.319, P < 0.01), but there was no significant difference in the proportion of treatment options between the patients with POTS and the patients with VVS. CONCLUSION POTS and VVS in children are the main underlying diseases of OI, while SI is a new disease discovered recently. The number of children with OI and SI showed an increasing trend. The main treatment methods are autonomic nerve function exercise and ORS. Children with VVS coexisting with POTS were more likely to take pharmacological treatments than those with VVS or POTS only.
Child ; Electrolytes ; Female ; Humans ; Male ; Metoprolol ; Midodrine ; Orthostatic Intolerance/therapy* ; Postural Orthostatic Tachycardia Syndrome/diagnosis* ; Retrospective Studies ; Salts ; Sitting Position ; Syncope, Vasovagal/diagnosis* ; Tilt-Table Test

OBJECTIVE: To explore the influence of individual characteristics of patients on the kinematics parameters of sitting lumbar spine manipulation. METHODS: From January 2016 to December 2016, 30 patients with degenerative lumbar spondylolisthesis were treatede, including 18 males and 12 females, aged from 45 to 61(52.33±2.34) years old, with a course of 2 to 72(29.13±3.23) months. Motion capture technique was used to measure the kinematics parameters of the same manipulator in sitting lumbar spine manipulation for 30 patients, including rotation time, maximum speed and maximum acceleration. The parameters of the left and right hands of the operator were different. The effects of individual characteristics on the kinematics parameters of sitting lumbar spine manipulation were analyzed. RESULTS: The kinematic and mechanical parameters of manipulation were as follows:spin time, maximum speed, maximum acceleration, the manipulation done by right or left hand showed the similar parameters(>0.05). According to multivariate linear regression, there was a significant correlation between the age of the patient and the rotation time of the operator(<0.01); the height of patient had a significant correlation with the maximum speed and maximum acceleration of the operator(<0.01). CONCLUSIONS There is no difference between the manipulation of left and right hand in clinical application. Age and height are important influencing factors of sitting lumbar rotation manipulation.
Biomechanical Phenomena ; Female ; Humans ; Lumbar Vertebrae ; Male ; Manipulation, Spinal ; Middle Aged ; Range of Motion, Articular ; Sitting Position