Supertraining

Just a note to forum members that the much anticipated study from the  
Houston group "The fastest runner on artificial legs: different limbs,  similar 
function?"  (Weyand, Bundle, McGowan, Grabowski, Brown, Kram,  and Herr 
about the testing of Oscar Pistorius is now available at  Journal of Applied 
Physiology (in press).
 
Ken Jakalski
Lisle High School
Lisle, IL USA

The fastest runner on artificial legs: different limbs, similar function?
Peter G. Weyand1, Matthew W. Bundle2, Craig P. McGowan3, Alena M. Grabowski4,
Mary Beth Brown5, Rodger Kram6*, and Hugh M. Herr4

J Appl Physiol (June 18, 2009). doi:10.1152/japplphysiol.00174.2009

The recent competitive successes of a bilateral, transtibial amputee sprint
runner who races with modern running prostheses has triggered an international
controversy regarding the relative function provided by his artificial limbs.
Here, we conducted three tests of functional similarity between this amputee
sprinter and competitive male runners with intact limbs: the metabolic cost of
running, sprinting endurance, and running mechanics. Metabolic and mechanical
data, respectively, were acquired via indirect calorimetry and ground reaction
force measurement during constant-speed, level treadmill running. First, we
found that the mean gross metabolic cost of transport of our amputee sprint
subject (174.9 ml O2 kg-1 km-1; speeds: 2.5 to 4.1 m s-1) was only 3.8% lower
than mean values for intact-limb elite distance runners and 6.7% lower than for
sub-elite distance runners, but 17% lower than for intact-limb 400-meter
specialists (210.6 [13.2; SD] ml O2 kg-1 km-1). Second, the speeds our amputee
sprinter maintained for six all-out, constant-speed trials to failure (speeds:
6.6-10.8 m s-1; durations: 2-90 s) were within 2.2 [0.6]% of those predicted for
intact-limb sprinters. Third, at sprinting speeds of 8.0, 9.0 and 10.0 m s-1,
our amputee subject had longer foot-ground contact times (+14.7 [4.2]%), shorter
aerial (-26.4 [9.9]%) and swing times (-15.2 [6.9]%), and lower stance-averaged
vertical forces (-19.3 [3.1]%) than intact-limb sprinters (top speeds = 10.8
vs.10.8 [0.6] m s-1).

We conclude that running on modern, lower-limb sprinting prostheses appears to
be physiologically similar, but mechanically different than running with intact
limbs.