Table 4. Regardless of what further research shows, either prostheses will be banned from professional sprinting or they will be permitted in some form. If any athlete with prosthetic legs exhibited a 400 m performance metric that was better than that observed by the best NA athlete or over two standard deviations better than the average of elite NA athletes (consistent with [17]), prosthetic legs likely confer a specific advantage in that metric compared to biological legs. The difference between the sprint endurance profile versus the corresponding race splits may be related to typical variability in sprint endurance profiles, differences in race strategies and/or environmental conditions. Case studies in physiology: the biomechanics of the fastest sprinter with a unilateral transtibial amputation, Faster top running speeds are achieved with greater ground forces not more rapid leg movements, Limitations to maximum running speed on flat curves, Running on flat turns: experiments, theory, and applications, Running economy of elite male and elite female runners, Ten kilometer performance and predicted velocity at VO2max among well-trained male runners, Energetics of high-speed running: integrating classical theory and contemporary observations, Sprint performance-duration relationships are set by the fractional duration of external force application, Prosthetic shape, but not stiffness or height, affects the maximum speed of sprinters with bilateral transtibial amputations, The biological limits to running speed are imposed from the ground up. Faculty-Staff Email Archive Student Email Archive Graduate Student Email Archive New Buffs Email Archive Senior Class Student Email Archive CommunityEmail Archive COVID-19 Digest Archive, University of Colorado Boulder Regents of the University of Colorado Figure 2. If you compare Oscar to six of the former and current world record holders, he swings his legs 15 percent faster., Kram and his colleagues at MIT have since been collecting data on a different set of sprinters single-limb amputees comparing the way they swing their natural legs to their artificial ones. from NA athlete Avg) [17]. cut-off, the fastest BA's four 100 m race splits were slower, non-different, non-different, and faster than those of elite NA athletes from the 2017 IAAF World Championships, resulting in similar 400 m race times between the fastest BA and elite NA athletes (less than 1 s.d. Posted by Bryan Potok, CPO on September 10, 2019. 
Are running speeds maximized with simple-spring stance mechanics? We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites. This means that the length of the leg does not have any significant effect on speed. Blake Leeper, paralympic medalist and double amputee, gets tested and trains with Alena Grabowski, associate professor of integrative physiology at CU Boulder, over the course of several days in August 2018. The difference lies in the foot. A rare point of agreement: more research is necessary. One would think that before leveling an opinion on this, the scientific community should conduct more research.. Kram and company cite Weyands previous writings claiming vertical ground reaction force is the key determinant of sprinting speed. The passive nature of prosthetic limbs is the reasona sprinter needs to use a different prosthesis than that of a marathon runner. The long-awaited study, published in Royal Society Open Science, provides the most comprehensive set of data ever collected from elite runners with bilateral leg amputations, including the worlds fastest 400-meter sprinter, Blake Leeper. Subsequently, we compared the best performance metric value achieved across all athletes with prosthetic legs to those across all NA athletes. http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
This gives the muscles some leeway, so it doesnt have to work hard to sustain every step while running. A specific wavelength of ultraviolet light is not only extremely effective at killing the virus that causes COVID-19, but is also safer for use in public spaces, finds new CU Boulder research. Currently, some scientists posit that using prosthetic versus biological legs enable athletes to achieve faster maximum running velocities [7] and run while expending less metabolic energy (better running economy) [9], factors that presumably improve running performance [10]. The greatest Vo2 value (Vo2peak) for each athlete and cohort is indicated by a square around the symbol. Sprint endurance. Figure 3. For comparison, on the same and similar curve radius (36.5 m and 37.72 m), the maximum running velocity of NA athletes is reported to be 3% and 4.7% slower than on a straightaway, respectively (figure 4) [21,32]. As prosthetic technology continues to improve, researchers are continually trying to find answers to whether prostheses provide adaptive athletes unfair advantage over competitors with biological limbs or not. Fuel was added to the debate in 2014 when Markus Rehm, a German national long jump champion, was barred from competing in the European Championships in Zurich. They encourage other researchers to publish more data. But Kram and company also argue that while Pistorius leg repositioning time is swift, its not unnaturally so. The fastest runner on artificial legs: different limbs, similar function? After a year-long study of the case of Oscar Pistorius, two starkly opposing scientific camps emerge on each side of the debate, By Running lane, consecutive 100 m race split times and 400 m race times for elite non-amputee athletes competing in the 400 m final of the 2017 International Association of Athletics Federations (IAAF) World Championship [, Leg stiffness of sprinters using running-specific prostheses, Running-specific prostheses limit ground-force during sprinting, Characterizing the mechanical properties of running-specific prostheses, Point: artificial limbs do make artificially fast running speeds possible, Counterpoint: artificial legs do not make artificially fast running speeds possible, Biomechanics of double transtibial amputee sprinting using dedicated sprinting prostheses, High-speed running performance: a new approach to assessment and prediction, Optimal starting block configuration in sprint running: a comparison of biological and prosthetic legs, Sprint start kinetics of amputee and non-amputee sprinters, Maximum-speed curve-running biomechanics of sprinters with and without unilateral leg amputations, Running-specific prostheses permit energy cost similar to nonamputees, Athletes with versus without leg amputations: different biomechanics, similar running economy, Sprint mechanics in world-class athletes: a new insight into the limits of human locomotion. We measured the fastest BA's Vo2 and Vco2 throughout each trial. The goal is to get as high in the air as possible without losing forward velocity. Another difference is its adaptability. All authors were involved in the following legal cases: Court of Arbitration in Sport, Leeper versus World Athletics, 2020 and 2021. During the initial 100 m, the fastest BA was 8.3% slower (greater than 7 s.d.) Because of these two high-profile athletes, an investigation was launched into the nature of running blades and whether they give adaptive athletes an unfair advantage over their competition or not. (d) The time it takes to accelerate from stationary starting blocks to 20 m for elite NA athletes (gold), sub-elite NA athletes (silver) [16] and the fastest BA (red). This means that amputee runners need to exert more effort while running. To accomplish this goal, we measured the following 400 m performance metrics from the athlete who ran the fastest-ever 400 m time using prosthetic legs (fastest BA) following his competition season where he ran 400 m in 44.42 s: initial race acceleration [11,16], maximum straightaway running velocity [3,1719], maximum curve running velocity [13,20,21], running velocity at aerobic capacity (vVo2peak) [17,22,23] and sprint endurance [10,17,24,25]. The potential for athletes with leg amputations to race alongside NA Olympians has been impeded by policymakers who have banned the use of running-prostheses from sanctioned NA competition [5]. of the velocity versus time data collected from the fastest BA's three maximum acceleration trials. Error bars for NA athletes indicate SE across athletes and for the fastest BA indicates s.d. Electronic supplementary material is available online at https://doi.org/10.6084/m9.figshare.c.5764186. Pistorius eventually prevailed. Running lane, consecutive 100 m race split times and 400 m race times for elite non-amputee athletes competing in the 400 m final of the 2017 International Association of Athletics Federations (IAAF) World Championship [30] and the fastest BA competing in Prague in 2018, where he ran his best time prior to this study. from the Avg of NA athlete values) [17] (figures 2 and 3). There are many disadvantages to consideron the part of the adaptive athlete such as energy loss, limitations in ankle push-off during acceleration, and energy loss, among others. In a point-counterpoint published by the Journal for Applied Physiology today, Dr. Peter Weyand of Southern Methodist University and Dr. Matthew Bundle of the University of Wyoming claim sprinters prosthetic legs can shave more that 10 seconds from a runners 400-meter. On the treadmill and track, researchers measured Leepers acceleration out of the starting blocks, maximum speed along straight-aways and around curves, velocity at aerobic capacity and sprint endurance (all-out effort). associate professor of integrative physiology at CU Boulder, The authors presented preliminary results to the Court of Arbitration for Sport in 2020 but the court ruled that Leeper could not participate in World Athletics-sanctioned events, including the Olympics, because his prostheses made him too tall. Error bars for NA athletes indicate SE across athletes and for the fastest BA indicates s.d. Further, the best experimentally measured initial race acceleration (from 0 to 20 m), maximum velocity around curves, and velocity at aerobic capacity of athletes with prosthetic legs were 40%, 13% and 19% slower compared to NA athletes, respectively. Despite functional differences, the use of running prostheses allows athletes with leg amputations to race 400 m shoulder-to-shoulder with non-amputee (NA) athletes at every competitive levelfrom youth athletics to the Olympic Games. 
Table 2. Experimental data from this study are located in the paper and electronic supplementary material. Thus, based on a 2 s.d. from NA athlete Avg) [17].Download figureOpen in new tabDownload PowerPointFigure 3. All authors gave final approval for publication and agreed to be held accountable for the work performed therein. Maximum curve running velocity trials for non-amputee athletes (NA, silver circles), and the fastest 400 m athlete with bilateral leg amputations (fastest BA, red diamonds) using running-prostheses on different curve radii [21,32]. Pistorius went on to become the first amputee to compete in the Olympics at the 2012 Olympics in London. The energy is then released as the runner pushes off the ground. Do carbon-fiber prostheses give adaptive athletes an advantage over their non-amputee competitors? Not only is it difficult to weigh the importance of these purported pros and cons, but many hypothetical performance differences between athletes using prosthetic or biological legs have been contested by experimental data [14,15]. First, the fastest BA's fastest race split (100200 m) may have been slower than his maximum treadmill velocity because he ran further on the track versus the treadmill (31 versus 100 m) [10,25]. Submaximal and maximal rates of oxygen uptake (Vo2) versus running velocity for non-amputee 400 m athletes (NA 400 m, silver circles) [17], non-amputee distance runners (NA dist run, black circles) [34] and the fastest (fastest BA, red diamonds) and second fastest (2nd fastest BA, blue diamonds) 400 m athletes with bilateral leg amputations using running-prostheses. Powered by Passion. Notably, Mero et al. We compared these data to those of previous studies that involved NA athletes and the 2nd fastest BA, who performed 26 sprint endurance trials per session, totaling 615 trials per participant [10,17]. A faster leg swing and an energy-efficient stride can create up to a seven-second lead. As the fastest BA approached his maximum velocity, we implemented smaller treadmill velocity increments (e.g. The maximum velocity testing protocol was identical between the fastest BA, fastest athlete with a unilateral leg amputation [18] and fastest NA athletes [29]. Aerobic metabolism and perceived exertion for the fastest athlete with prosthetic legs across a range of submaximal running velocities. After each blood sample, the fastest BA immediately initiated the subsequent running trial. The fastest BA's vVo2peak (4.3 m s1) was 14% slower than that reported by the 2nd fastest BA (vVo2peak: 5.0 m s1) [17]. E-skin Enables Robots To Feel Pain, May Improve Future Prosthetic Limbs, Hawaii Man Finishes First Solo Voyage Around the World by a Double Amputee, Double Amputee Honored With Amelia Earhart Award, Why A One-Week Social Media Cleanse Is Good for You, Natural Ways To Improve Your Insulin Sensitivity. For athletes like Pistorius, that means waiting in athletic purgatory until science decides whether the lack of biological limbs constitutes a handicap or a performance enhancement. Namely, the international governing body for the sport of athletics (World Athletics) enacted a rule from 2015 to 2020 that prohibited the use of a mechanical aid (e.g.
Once the prosthesis has been fitted to the runner, it is also custom-optimized to run under specific conditions. The vertical dashed lines indicate the velocity at Vo2peak. Over the fourth and final 100 m, the fastest BA ran 9.9% faster (greater than 3 s.d.) However, its not all bad news. Weyand and Bundle respond that more erect limb posture in leg-amputees, coupled with lower ground force co-reduce the muscular forces required to attain the same sprint running speeds to less than half of intact-limb levels, saying Pistorius needs half the strength to reach the same speeds as runners on biological legs. Average (Avg) vertical (vGRF) and horizontal (hGRF) ground reaction forces (GRFs) on the starting blocks, force application time on the starting blocks (time) and horizontal velocity out of the starting blocks for the fastest 400 m athlete with bilateral leg amputations using prosthetic legs (fastest BA), non-amputee athletes (NA), and athletes with unilateral leg amputations (UA). Based on these data, the fastest BA does not have a relatively faster maximum curve running velocity than previously tested NA athletes. Sprint endurance velocity that the fastest 400 m athlete with bilateral leg amputations using running-prostheses could sustain for a given time, and the corresponding velocity modelled for non-amputee athletes with the same maximum running velocity and velocity at aerobic capacity (equation (6.9)) [10]. Between each acceleration trial, the fastest BA recovered for at least 5 min. Two male athletes with bilateral leg (transtibial) amputations have run 400 m faster than the Olympic athletics (track and field) qualifying standard. We compared data from the fastest BA to those of NA athletes from a previous study who performed two maximum effort accelerations out of the starting blocks along a straightaway over distances of 010, 015, 020, 030 and 040 m [16]. The sprint endurance time for a given velocity is nearly identical for the fastest athlete with prosthetic legs (fastest BA) and non-amputee (NA) athletes. The point-counterpoint article published today hopes to wring consensus from the scientific community. The ban was rescinded, but the new data seems little more conclusive as research team members draw lines in the sand. Sign up to receive Popular Science's emails and get the highlights. (a) The sum of the average (Avg) horizontal ground reaction force (hGRF) relative to body weight (BW) on the starting blocks versus time from the front and back legs of the fastest 400 m athlete with bilateral leg amputations using running-prostheses (fastest BA, red dashed line), and sub-elite non-amputee athletes (NA, black solid line) [11]. Its an opinion piece that has not been peer reviewed., The study Kram refers to is Weyand and Bundles comparison of Pistorius to physiological data collected on other sprinters. from NA distance runners (5 km PRs: 13:34 to 13:59 m:s; 10 km PRs: 28:36 to 29:21 m:s) [37]. : conceptualization, data curation, formal analysis, investigation, methodology, validation, visualization, writingreview and editing; A.M.G. When comparing performance data from Leeper, South African blade runner Oscar Pistorius and up to six other bilateral amputee sprinters with those of the best non-amputee sprinters in the world across five performance metrics, the research found no advantage. Butaccording to Toboga, although longer legs can mean taking longer steps, it can also take a bit longer to swing the leg, resulting in fewer steps.
In fact, its significantly faster. Once an amputee runner reaches top speed, the blade prostheses allow him or her to move faster and with less effort. Athletes run along a curve for over half of a 400 m race, which is notable because athletes run slower on curves than on a straightaway [13,21].
At 10 m s1, the fastest BA generated 5% lower relative stance Avg vGRFs, 7% longer contact lengths and times and 1% faster step frequencies compared to non-amputee athletes (all parameters less than 2 s.d.