Leg stiffness and sprint ability in amputee sprinters.
BACKGROUND
Understanding leg stiffness (K (leg)) in amputee sprinters is important for the evaluation of their sprint ability and development of running-specific prostheses (RSP).


OBJECTIVE
To investigate K (leg) during hopping in amputee sprinters.


METHODS
Cross-sectional study.


METHODS
Seven transtibial (TT) and seven transfemoral (TF) amputee sprinters, as well as seven non-active able-bodied subjects, performed one-legged hopping matching metronome beats at 2.2 Hz. Amputees hopped on their sound limb whereas able-bodied (AB) subjects hopped on their dominant limb. Using a spring-mass model, K (leg) was calculated from the subjects' body mass, ground contact and flight times.


RESULTS
Both TT and TF sprinters demonstrated significantly higher K (leg) than AB subjects. K (leg) during hopping on the sound leg significantly correlated with personal records attained in a 100-m sprint in both TT (r = -0.757) and TF sprinters (r = -0.855).


CONCLUSIONS
The results of the present study suggest that amputee sprinters have a greater K (leg) during hopping than inactive non-amputees, and that their sprint ability can be predicted from the K (leg) during hopping at 2.2 Hz on the sound limb.
Research Institute, National Rehabilitation Center for Persons with Disabilities, Department of Rehabilitation for the Movement Functions, Namiki 4-1, Tokorozawa, Saitama, Japan. hobara-hiroaki@rehab.go.jp
Hiroaki
H
Hobara
Shuichi
S
Tominaga
Shingo
S
Umezawa
Koudai
K
Iwashita
Atsuo
A
Okino
Taku
T
Saito
Fumio
F
Usui
Toru
T
Ogata
D000328:Adult; D000674:Amputees; D001186:Artificial Limbs; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D005260:Female; D005269:Femur / Q000601:surgery; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D008432:Mathematical Computing; D011474:Prosthesis Design; D012420:Running / Q000502:physiology*; D013977:Tibia / Q000601:surgery