Sit-to-stand (STS) transfer training is probably the most demanding task in rehabilitation. We have developed an innovative STS trainer that offers variable levels of mechanical support and speeds of STS transfer. In a group of neurologically intact individuals we compared kinematics, kinetics and electromyography (EMG) patterns of STS transfer assessed in three experimental conditions with increasing degree of mechanical support (MIN STS-T, MED STS-T and MAX STS-T) to natural, unassisted STS movement (NO STS-T). The resulting ankle, knee, hip joint and trunk angles in experimental conditions MED STS-T and MIN STS-T were very similar to experimental condition NO STS-T. Vertical ground reaction forces and EMG patterns in the tibialis anterior, quadriceps and hamstrings show a clear trend toward %normal% patterns as the level of mechanical support from the device is progressively reduced. We have further tested the feasibility of the STS trainer in five stroke subjects at two levels of support showing that increased voluntary effort is needed when the support is reduced. Based on these results we conclude that negligible constraints are imposed by the device on a user's STS transfer kinematics, which is an important prerequisite for considering clinical use of the device for training in neurologically impaired.
COBISS.SI-ID: 2037353
In this study we developed a sensor-supported computer model for head movement analysis of infants during rehabilitation. The model is based on data processing and sensory fusion methodology, comprising data of pressure mattress and wireless inertial and magnetic measurement units. Data comparison to referential measurement results of infants confirms adequacy of the proposed approach with combined use of search algorithms, including line-of-sight algorithm, histogram analysis, and the head-tracking algorithm. Methodology is directly related to the EU FP7 project CareToy and intended for tele-rehabilitation of pre-term infants.
COBISS.SI-ID: 10918740
The study uses inertial sensors to measure ski jumper kinematics and joint dynamics, which was until now only a part of simulation studies. For subsequent calculation of dynamics in the joints, a link-segment model was developed. The model relies on the recursive Newton-Euler inverse dynamics. This approach allowed the calculation of the ground reaction force at take-off. For the model validation, four ski jumpers performed a simulated jump in a laboratory environment on a force platform. The results fit well to the reference system. For field tests, six jumpers participated in the study. The proposed system was able to indirectly provide the values of forces and moments in the joints of the ski-jumpers’ body segments, as well as the ground reaction force during the in-run and take-off phases in comparison to the force platform installed on the table. Kinematics assessment and estimation of dynamics parameters can be applied to jumps from any ski jumping hill.
COBISS.SI-ID: 11022420
We developed a system that uses physiological responses (heart rate, skin conductance, respiration, skin temperature, eye movement, pupil size and electroencephalography) to quantify different aspects of a person’s workload (cognitive, physical, temporal etc.). It was tested with ten healthy users who performed different tasks using an arm exoskeleton.
COBISS.SI-ID: 10738004
The purpose of the study was a biodynamic analysis of the kinematic, dynamic and EMG parameters of two types of drop jumps (heights of 25 cm and 45 cm). The sample of measured subjects included four female elite triple jump athletes, with their best results varying from 13.33 to 15.06 meters. The kinematic and dynamic parameters were calculated with the use of a bipedal tensiometric force plate, which was synchronized with nine CCD cameras. A 16- channel electromyography(BTS Pocket, Myolab) was used to analyze the EMG activation of the following muscles: m. erector spinae, m.gluteus, m. rectus femoris, m. vastus medialis, m. vastus lateralis, m. biceps femoris, m. soleus and m. gastrocnemius medialis. In the drop jump from a 25 cm height, the measured subjects achieved the following results: height of jump 43.37±5.39 cm and ground reaction force 2770±411 N. In comparison, results for the drop jump from a 45 cm height were: height of jump 45.22±4.65 cm and ground reaction force 2947±366 N. Vertical velocity of the take-off in the 25 cm drop jump was 2.77±0.19 ms–1 and in the 45 cm drop jump it was 2.86±0.15 ms–1. Observation of the EMG activation revealed the proximal to distal principle of muscle activation at work in both types of drop jumps. In the fi rst phase of the concentric phase the most active muscles were m. gluteus maximus and m. rectus femoris. The greatest activity of m. gastrocnemius medialis and m. soleus was noticed in the last third of the take-off action. Signifi cantly high EMG activation of m. vastus medialis and m. vastus lateralis was already shown in the fl ight phase prior to the feet making contact with the ground.
COBISS.SI-ID: 4716721