European Journal of Applied Physiology

, Volume 113, Issue 3, pp 599–609

Impact reduction during running: efficiency of simple acute interventions in recreational runners

Authors

  • Marlène Giandolini
    • University of Lyon
    • Laboratory of Exercise Physiology (EA4338)
  • Pierrick J. Arnal
    • University of Lyon
    • Laboratory of Exercise Physiology (EA4338)
  • Guillaume Y. Millet
    • University of Lyon
    • Laboratory of Exercise Physiology (EA4338)
  • Nicolas Peyrot
    • University of La Réunion, UFR SHE, CURAPS-DIMPS (EA4075)
  • Pierre Samozino
    • Laboratory of Exercise Physiology (EA4338)University of Savoie
  • Blaise Dubois
    • Faculty of MedicineUniversity of Laval
    • University of Lyon
    • Laboratory of Exercise Physiology (EA4338)
    • Laboratoire de Physiologie de l’Exercice (EA4338), Médecine du Sport-Myologie CHU BellevueUniversité de Saint-Etienne
Original Article

DOI: 10.1007/s00421-012-2465-y

Cite this article as:
Giandolini, M., Arnal, P.J., Millet, G.Y. et al. Eur J Appl Physiol (2013) 113: 599. doi:10.1007/s00421-012-2465-y

Abstract

Running-related stress fractures have been associated with the overall impact intensity, which has recently been described through the loading rate (LR). Our purpose was to evaluate the effects of four acute interventions with specific focus on LR: wearing racing shoes (RACE), increasing step frequency by 10 % (FREQ), adopting a midfoot strike pattern (MIDFOOT) and combining these three interventions (COMBI). Nine rearfoot-strike subjects performed five 5-min trials during which running kinetics, kinematics and spring-mass behavior were measured for ten consecutive steps on an instrumented treadmill. Electromyographic activity of gastrocnemius lateralis, tibialis anterior, biceps femoris and vastus lateralis muscles was quantified over different phases of the stride cycle. LR was significantly and similarly reduced in MIDFOOT (37.4 ± 7.20 BW s−1, −56.9 ± 50.0 %) and COMBI (36.8 ± 7.15 BW s−1, −55.6 ± 29.2 %) conditions compared to NORM (56.3 ± 11.5 BW s−1, both P < 0.001). RACE (51.1 ± 9.81 BW s−1) and FREQ (52.7 ± 11.0 BW s−1) conditions had no significant effects on LR. Running with a midfoot strike pattern resulted in a significant increase in gastrocnemius lateralis pre-activation (208 ± 97.4 %, P < 0.05) and in a significant decrease in tibialis anterior EMG activity (56.2 ± 15.5 %, P < 0.05) averaged over the entire stride cycle. The acute attenuation of foot–ground impact seems to be mostly related to the use of a midfoot strike pattern and to a higher pre-activation of the gastrocnemius lateralis. Further studies are needed to test these results in prolonged running exercises and in the long term.

Keywords

Loading rate Muscular activity Running pattern Footwear Step frequency

Abbreviations

BF

Biceps femoris

BW

Body weight

F max

Maximal vertical ground reaction force

Fz1

Magnitude of impact force peak

GL

Gastrocnemius lateralis

k leg

Leg stiffness

k vert

Vertical stiffness

LR

Vertical mean loading rate

MFS

Midfoot strike

PSF+10%

Preferred step frequency increased by10 %

RFS

Rearfoot strike

t a

Aerial time

TA

Tibialis anterior

t c

Contact time

tFz1

Time to impact peak

VGRF

Vertical ground reaction force

VL

Vastus lateralis

ΔL

Maximal leg spring compression during contact

Δz

Vertical maximal downward displacement of the center of mass during contact

Copyright information

© Springer-Verlag 2012