sprint for sprinters with UTT using running-specific prosthesis is an individual occurrence. Consequently, as noted by a previous study, 2 an average group-based analysis may mask important issues at the individual level. In the present study, we classified 2 and 2 sprinters with UTT into step frequency
Hiroaki Hobara, Sakiko Saito, Satoru Hashizume, Hiroyuki Sakata and Yoshiyuki Kobayashi
Gerda Strutzenberger, Adam Brazil, Timothy Exell, Hans von Lieres und Wilkau, John D. Davies, Steffen Willwacher, Johannes Funken, Ralf Müller, Kai Heinrich, Hermann Schwameder, Wolfgang Potthast and Gareth Irwin
, Interantional Paralympic Committee; PB, personal best; RSP, running-specific prosthesis; UTF, unilateral transfemoral; UTT, unilateral transtibial; WR, world record. Hence, the mean performance of the AB and AMP groups was 11.4% (3.4%) and 11.2% (5.7%) slower than the current 100-m sprint world record of each
Atsushi Makimoto, Yoko Sano, Satoru Hashizume, Akihiko Murai, Yoshiyuki Kobayashi, Hiroshi Takemura and Hiroaki Hobara
Understanding the characteristics of ground reaction forces (GRFs) on both limbs during sprinting in unilateral amputees wearing running-specific prostheses would provide important information that could be utilized in the evaluation of athletic performance and development of training methods in this population. The purpose of this study was to compare GRFs between intact and prosthetic limbs during sprinting in unilateral transfemoral amputees wearing running-specific prostheses. Nine sprinters with unilateral transfemoral amputation wearing the same type of prosthesis performed maximal sprinting on a 40-m runway. GRFs were recorded from 7 force plates placed in the center of the runway. Peak forces and impulses of the GRFs in each direction were compared between limbs. Peak forces in vertical, braking, propulsive, and medial directions were significantly greater in intact limbs than those in prosthetic limbs, whereas there were no significant differences in peak lateral force between limbs. Further, significantly less braking impulses were observed in prosthetic limbs than in intact limbs; however, the other measured impulses were not different between limbs. Therefore, the results of the present study suggest that limb-specific rehabilitation and training strategies should be developed for transfemoral amputees wearing running-specific prostheses.
Lara Grobler, Suzanne Ferreira and Elmarie Terblanche
The Paralympic Games have undergone many changes since their inception in 1960, one being the advances made in running-specific prostheses (RSPs) for track athletes with lower-limb amputations.
To investigate the sprinting-performance changes in athletes with lower-limb amputations since 1992 to assess whether the influence of developments in RSP technology is evident.
The results of the Olympic and Paralympic Games ranging between 1992 and 2012 for the 100-m and 200-m were collected, and performance trends, percentage change in performance, and competition density (CD) were calculated.
The results indicate that the greatest performance increases were seen in athletes with lower-limb amputations (T42 = 26%, T44 = 14%). These performance improvements were greater than for Olympic athletes (<3%), as well as Paralympic athletes from other selected classes (<10%). The T42 and T44 classes also showed the lowest CD values.
These results suggest that although there is an overall trend for improved Paralympic sprint performances, RSP technology has played a noteworthy role in the progression of performances of athletes with amputations. It is also hypothesized that the difference in the performance improvements between the T42 and T44 classes is due to the level of disability and therefore the extent to which technology is required to enable locomotion.
It is evident that RSP technology has played a significant role in the progression of performances in athletes with lower-limb amputations.
Brian S. Baum, Hiroaki Hobara, Yoon Hyuk Kim and Jae Kun Shim
Individuals with lower extremity amputation must adapt the mechanical interactions between the feet and ground to account for musculoskeletal function loss. However, it is currently unknown how individuals with amputation modulate three-dimensional ground reaction forces (GRFs) when running. This study aimed to understand how running with running-specific prostheses influences three-dimensional support forces from the ground. Eight individuals with unilateral transtibial amputations and 8 control subjects ran overground at 2.5, 3.0, and 3.5 m/s. Ten force plates measured GRFs at 1000 Hz. Peak and average GRFs and impulses in each plane were compared between limbs and groups. Prosthetic limbs generated reduced vertical impulses, braking forces and impulses, and mediolateral forces while generating similar propulsive impulses compared with intact and control limbs. Intact limbs generated greater peak and average vertical forces and average braking forces than control subjects’ limbs. These data indicate that the nonamputated limb experiences elevated mechanical loading compared with prosthetic and control limbs. This may place individuals with amputation at greater risk of acute injury or joint degeneration in their intact limb. Individuals with amputation adapted to running-specific prosthesis force production limitations by generating longer periods of positive impulse thus producing propulsive impulses equivalent to intact and control limbs.