COMPARISON OF ANGLES AND THE CORRESPONDING MOMENTS IN KNEE AND HIP DURING RESTRICTED AND UNRESTRICTED SQUATS

The aim of this study is the comparison of angles and the corresponding moments in knee and hip during squatting. The five subjects performed restricted and unrestricted squats. The experimental set-up consisted of a motion capture system and two force plates. The loading conditions were 0, ¼ and ½ BW. The moments and the force were calculated using inverse dynamics. Overall, the maximal moments were observed in the knee during unrestricted squats and in the hip during restricted squats. Comparing the moments at a knee angle of 60º, the loading conditions have a larger influence than the type of execution. The moment in the knee is 10.4%, respectively 11.2% lower with ¼ and ½ body weight during restricted squats. In the hip, the moment is 15.5 %, respectively 14 % higher for the same conditions. The angle of the hip remains rather constant. This most likely implies a higher load to the lower back. Hence, the exercise instruction should be adapted to the aims and the training condition of the athlete

Effects of Foot Orthoses on Skeletal Motion During Running

Objective. To quantify the effects of medial foot orthoses on skeletal movements of the calcaneus and tibia during the stance phase in running. Design. Kinematic effects of medial foot orthoses (anterior, posterior, no support) were tested using skeletal (and shoe) markers at the calcaneus and tibia. Background. Previous studies using shoe and skin markers concluded that medially placed orthoses control/reduce foot eversion and tibial rotation. However, it is currently unknown if such orthoses also affect skeletal motion at the lower extremities. Methods. Intracortical Hofman pins with reflective marker triads were inserted under standard local anesthetic into the calcaneus and tibia of five healthy male subjects. The three-dimensional tibiocalcaneal rotations were determined using a joint coordinate system approach. Eversion (skeletal and shoe) and tibial rotation were calculated to study the foot orthoses effects. Results. Orthotic effects on eversion and tibial rotations were found to be small and unsystematic over all subjects. Differences between the subjects were significantly larger (pp\u3c0.05). Conclusions. This in vivo study showed that medially placed foot orthoses did not change tibiocalcaneal movement patterns substantially during the stance phase of running. Relevance Orthoses may have only small kinematic effects on the calcaneus and tibia (measured with bone pins) as well as on the shoes (measured with shoe markers) during running of normal subjects. Present results showed that orthotic effects were subject specific and unsystematic across conditions. It is speculated that orthotic effects during the stance phase of running may be mechanical as well as proprioceptive

Veränderte Aktivierung der Vasti während dem Laufen als Merkmal des PFPS

Current literature discusses whether an earlier activation of the Vastus lateralis (VL) compared to the Vastus edialis obliquus (VMO) calculated relative to the heelstrike during running can be associated with the Patellofemoral Pain Syndrome (PFPS). The present study investigated the onset of the activity of both Vasti for a healthy control group (n = 12) and subjects suffering from PFPS (n = 14) during barefoot, shod running, and running with insoles (if available). Based on repeated measurements of the healthy subjects it was estimated that time differences between individual onsets of muscle activation and the later activation of the VMO related to the VL should be at least 25–30 ms to exclude to a high probability an interpretation biased by the given variance of the measurement performed with surface electrodes. The present results show that time differences of the onset of the activity of the Vasti between the two investigated groups were all between 5 and 10 ms on average, not significant, and not clearly distinguishable from the given variance of the measurement. Furthermore, using insoles did not result in a more simultaneous activation of the Vasti before heelstrike. Thus, an earlier activation of the VL compared to the VMO can not be considered as a single characteristic of patellofemoral pain. However, future work should investigate whether the muscular coordination of the Vasti in combination with the kinematics and kinetics of the lower extremity can biomechanically explain the occurrence of individual patellofemoral pain

Quantifizierung von Gesichtsasymmetrien Eine Methode zur Objektivierung von Beeinträchtigungen der Gesichtsmotorik; eine Pilotstudie

ISSN:0013-5585ISSN:1862-278

The beta-spectrum of 35S^{35}S and search for the admixture of heavy neutrinos

The $\eta$-spectrum of $^{35}$S has been measured with highstatistical precision. A total of $2.2 \times 10^{10}$ eventshave been accumulated with a signal to background ratio of $10^{3}$ or better. A systematic search for neutrino mixing has been performedfor assumed neutrino masses up to 105 keV. In the mass range10 to 90 keV, an upper limit around $10^{-3}$ or less wasset for the mixing probability