0000000000088354
AUTHOR
Gert-peter Brüggemann
Muscle-tendon interaction and elastic energy usage in human walking
The present study was designed to explore how the interaction between the fascicles and tendinous tissues is involved in storage and utilization of elastic energy during human walking. Eight male subjects walked with a natural cadence (1.4 ± 0.1 m/s) on a 10-m-long force plate system. In vivo techniques were employed to record the Achilles tendon force and to scan real-time fascicle lengths for two muscles (medial gastrocnemius and soleus). The results showed that tendinous tissues of both medial gastrocnemius and soleus muscles lengthened slowly throughout the single-stance phase and then recoiled rapidly close to the end of the ground contact. However, the fascicle length changes demonstr…
Reactive Response and Adaptive Modifications in Dynamic Stability to Changes in Lower Limb Dynamics in the Elderly while Walking
The aim of this study was to examine the reactive responses and adaptive modifications in dynamic stability resulting from a unilateral change in lower limb dynamics in older and younger adults while walking. Eleven older (62- 76yrs) and eleven younger (22-30yrs) subjects walked on a treadmill and performed different gait conditions using an external resistance against lower limb movement. The margin of stability (MoS) at touchdown was calculated as the difference between base of support (BoS) and extrapolated centre of mass. After the resistance was turned on unexpectedly, older adults needed more steps to get back to the MoS baseline level due to a lower increase of the BoS. In the follow…
Characteristics of the early flight phase in the Olympic ski jumping competition.
Early flight phase (approximately 40 m) of the athletes participating in the final round of the individual large hill ski jumping competition in Salt Lake City Olympics was filmed with two high-speed pan & tilt video cameras. The results showed that jumpers' steady flight position was almost completed within 0.5s. The most significant correlation with the length of the jump was found in the angle between the skis and body (r=.714, p.001 at 1.1s after the take-off). This particular phase seemed to be important because the ski angle of attack was also related to the jumping distance at the same phase. Although the more upright ski position relative to flight path resulted in longer jumping di…
Comparison of the men's and the women's pole vault at the 2000 Sydney Olympic Games
The aim of this study was to identify differences between elite male and female pole vaulters in terms of their mechanical energy and angular momentum. The vaulter's total mechanical energy and angular momentum were calculated from the three-dimensional kinematic data of the pole vault finals at the Sydney 2000 Olympic Games. The development of total, kinetic and potential energy showed similar characteristics for men and women. The initial energy of the vault, the energy at maximum pole bend position and the final energy were significantly higher for male athletes (P0.05), while the energy gain produced by the athletes during the vault showed no significant differences (male vaulters 5.88 …
Individual muscle contributions to the in vivo achilles tendon force
OBJECTIVE: To ascertain the possibility of non-uniform stress within the achilles tendon due to individual force contributions of the triceps surae. DESIGN: Calculation of non-uniform stress through discrepancies in moments about the ankle joint. BACKGROUND: Non-uniform stress over the cross-sectional area have been implied in the etiology of achilles tendon injury and may influence functional aspects. However, this has not been empirically demonstrated. METHODS: In vivo achilles tendon forces were measured with an optic fibre technique during isometric plantarflexions at systematically varied knee angles and contraction intensities. A comparison to the plantar force measured underneath the…