Assessing Gait Stability before and after Cochlear Implantation

Background. It is known that cochlear implantation may alter the inner ear and induce vestibular disorders. Research Question. How does cochlear implantation influence gait stability? Material and Methods. An experimental group of twenty-one subjects scheduled for cochlear implantation underwent gait testing twice, on the day before cochlear implantation (BCI) and three months after cochlear implantation (ACI), using a motion capture system. A control group of 30 age-matched healthy individuals were also tested. Results. In the experimental group, the gait stability ratio (GSR) was found to improve in 17 subjects after implantation, by an average of 6%. Certain other parameters also showed statistically significant improvement between the two experimental group tests: step time (p<0.001), single-support phase walking speed (p<0.05), and center of mass (CoM) (p<0.05). Using the CoM results of the control group, we devised a stability classification system and applied it to the pre- and postimplantation subjects. After implantation, increases were seen in the number of subjects classified in interval II (strong stability) and III (weak stability). The number of subjects in interval I (perfect stability) decreased by 1 and in interval IV (no stability) by 4. Significance. (1) Although cochlear implantation intervenes in the vestibular area, we found evidence that gait stability improves in most subjects after the surgery, reducing the risk of falls. (2) We found statistically significant improvements in individual parameters (such as single-support phase time), in GSR, and in CoM. (3) Based on CoM results, we proposed a new rule-of-thumb way of classifying patients into gait stability intervals, for use in rehabilitation planning and monitoring

A comparison of acceleration in different body position during spinning

W ostatniej dekadzie można zauważyć coraz większe zainteresowanie akcelerometrią, jako jedną z metod oceny techniki ruchu człowieka. Akcelerometry pozwalają na pomiar przyśpieszenia poszczególnych segmentów oraz całego ciała. Spinning jest jedną z form rekreacji ruchowej, stanowiącej oryginalny program kolarstwa halowego i jest skierowany do ludzi w każdym wieku. Zajęcia polegają na pedałowaniu na stacjonarnym cykloergometrze w takt muzyki, gdzie każdy z uczestników indywidualnie reguluje wartość obciążenia. Problemem jest optymalny dobór obciążenia zewnętrznego i zachowanie odpowiedniej pozycji podczas jazdy. Z tego powodu w niniejszej pracy podjęto próbę wykorzystania pomiaru przyśpieszeń do charakterystyki różnych pozycji jazdy oraz wartości obciążeń działających na człowieka podczas spinningu.Accelerometry offers a practical and low cost method of objectively monitoring human movements, and has particular applicability to the monitoring of free-living subjects. The main objective of the paper is comparsion of acceleration in four different body position during spinning

Muscle force distribution during forward and backward locomotion

Backward walking (BW) is a common technique employed in the treatment of a variety of orthopedic and neurological diseases. BW training may offer some benefits especially in balance and motor control ability beyond those experienced through forward walking (FW). The purpose of this study was to determine whether BW represented a simple reversal of FW and, hence muscle force distribution is the same. The study involved one male healthy student of physical education (22 years, h = 185 cm, m = 80 kg). Measurements of spatial-temporal gait parameters were conducted using eight Vicon system cameras, and Kistler plates. Noraxon EMG was used to obtain muscles activity. OpenSim software was used to compute muscle force distribution during both types of gait. During FW and BW there is small difference for force curves produced by m. gluteus maximus (RMS = 0.04), m. biceps femoris short head (RMS = 0.19) and m. tibialis anterior (RMS = 0.16). Good validation by EMG signal was obtained for m. rectus femoris, m. biceps femoris short head, m. tibialis posterior during FW and BW. For m. iliacus, only during BW good validation was achived

Artificial neural network simulation of lower limb joint angles in normal and impaired human gait

Simulating the complexities of lower limb motion can be useful for orthosis or rehabilitation planning. The aim of this study was to develop an artificial neural network (ANN) able to accurately simulate the changes in the angle of the ankle, knee and hip joints during the gait cycle, then to use it to simulate the impact of a restricted range of ankle and hip joint angle changes on the progression of the knee joint angle. Methods: Thirty four young healthy students participated in the study. Gait kinematics data were collected using the Vicon system, then analyzed with an ANN. Results: We developed an ANN able to accurately simulate the progression of joint angles of lower-limb motion; its simulation of the impact of restricted ankle and hip joint angular ranges in the on the knee joint indicate that the braking phase is critical. Conclusions: ANNs offer a useful research method in clinical biomechanics. Further research in this vein should expand our understanding of compensatory functions in the lower limbs

Analysis of loads in step aerobics - literature review

Step aerobics jest jedną z bardziej popularnych form rekreacji ruchowej. Uważa się, że podwyższenie wysokości stopnia, lub zaaplikowanie w choreografii kroków typu high-impact zwiększa poziom trudności i intensywność zajęć, a w konsekwencji bardziej obciąża układ ruchu, co często prowadzi do kontuzji. Siła reakcji podłoża jest jedną ze zmiennych, która dostarcza informacji o obciążeniach. Niniejsza praca zawiera podsumowanie wyników, podawanych w literaturze, dotyczących zmian sił reakcji podłoża podczas najczęściej wykonywanych kroków aerobikowych.Step aerobics classes are offered at many gyms and fitness centers. The step aerobics is distinguished from other forms of aerobics exercise by its use of an elevated platform (the step). The height can be tailored to individual taste by inserting risers under the step. The main objective of the paper is description of human movement and vertical ground reaction forces during common steps in a simple choreography on the base of the various articles

The influence of the change of CoP on the errors in calculation of ankle joint moment during gait

Celem pracy jest przedstawienie analizy błędów oraz wyników symulacji wartości momentów sił w stawie skokowym dla płaskiego modelu kończyny dolnej, wynikających z różnego przebiegu środka parcia stopy na podłoże (CoP - center of pressure). Składowa przednio-tylna CoP była przesuwana o wektory [a;b], gdzie a i b - dowolne liczby rzeczywiste. Wartości uzyskane dla symulacji wskazują, że zmiana położenia CoP może generować bardzo duże błędy w wartościach momentów. Jak wynika z symulacji dla badanego modelu zmiana położenia CoP o wektor np. [0;7] cm, generuje krzywą tożsamą z trajektorią przebiegu momentów w stawie skokowym w chodzie charakterystycznym dla osoby niepełnosprawnej.The purpose of this study was to investigate the effect of errors in the center of pressure (CoP) locations on two dimensional lower limb joint moment during gait. Kinematics and kinetic data were synchronized in MatLab. Antero - posterior component of CoP was shifted by vectors [a;b], where a and b -real numbers. The study shows that change of the location of CoP can generate very large mistakes in calculation of joint moments. As results from simulation for studied model the change of CoP about the vector e.g. [0;7]cm, generate the curve the same like for the handicap person

Comparison of four methods of calculating the symmetry of spatial-temporal parameters of gait

Although gait symmetry is being evaluated and reported in the literature with increasing frequency, there is still no generally accepted standard for assessing symmetry, making it difficult to compare studies and establish criteria to guide clinical decision-making. The purpose of this study was to ascertain whether gait symmetry in healthy subjects is consistent when assessed using various coefficients (RI, SI, GA, and SA), and if possible to identify a gait symmetry coefficient with the highest diagnostic utility. The study involved a group of 58 healthy university-level students of physical education and secondary school students aged 20.03 ± 0.97. Measurements of spatial-temporal gait parameters were conducted using the ZEBRIS platform. Our analysis supports existing recommendations that the symmetry index (SI) should be used as the most sensitive assessment of gait symmetry on the basis of spatial-temporal parameters in healthy subjects. Moreover, we developed normative values of individual features for diagnostic purposes

Assessing the asymmetry of free gait in healthy young subjects

Purpose: The purpose of this study was to derive reference values for a four-level scale intended to evaluate variation in free gait asymmetry measurements in healthy subjects. Methods: This evaluation is based on kinetic values for the left and right lower limbs during gait, registered with advanced measurement systems and assessed using the symmetry index (SI) developed by Robinson. Results: For the majority of parameters, the SI does not follow normal distribution. As such, quartile values were used to create intervals for a four-step scale of assessing symmetry of free gait in healthy subjects for each studied gait parameter. The SI rating intervals were from 0% (very good symmetry) to 21.2% (very poor symmetry) for kinetic parameters. The poorest symmetry was observed for horizontal force F3. Conclusions: The four-step scale of assessing symmetry in free gait in healthy subjects can be used in diagnosing gait disorders, devising surgical treatment strategies, and monitoring the rehabilitation process. Reference values for intervals of symmetry indicators in healthy subjects can be used as criteria for comparing individuals with/without disabilities

Simulation of muscle forces in lower extremities while shot putting

W pracy wyznaczono czasowe przebiegi sił mięśniowych kończyn dolnych za pomocą modelu matematycznego u sportowca wykonującego pchnięcie kulą. Szczegółowo przedstawiono proces generowania symulacji w programie OpenSim na podstawie danych pochodzących z systemu Vicon Nexus. Zdefiniowany model ukazał, które mięśnie generują największą siłę w trakcie wykonywania ruchu pchnięcia kulą oraz które mięśnie pracują w warunkach ekscentrycznych. Istnieje możliwość wykorzystania wygenerowanego modelu do dalszych symulacji mających na celu szczegółową analizę techniki wykonywania pchnięcia kulą.Time trajectories of muscle forces for an athlete performing the shot put were modeled in the following article. The process of generating simulation in OpeSim software based on Vicon Nexus system data was presented in detail. The generated model showed which muscles generate the highest force while performing the movement of the shot put. It was also presented which muscles are working in eccentric conditions, which may cause injury. There is a possibility to use the generated model for further simulations, in order to conduct detailed analysis of shot put technique