TY  - JOUR
A1  - Prieske, Olaf
A1  - Mühlbauer, Thomas
A1  - Müller, Steffen
A1  - Krüger, Tom
A1  - Kibele, Armin
A1  - Behm, David George
A1  - Granacher, Urs
T1  - Effects of surface instability on neuromuscular performance during drop jumps and landings
JF  - European journal of applied physiology
N2  - The purpose of this study was to investigate the effects of surface instability on measures of performance and activity of leg and trunk muscles during drop jumps and landings.
 Drop jumps and landings were assessed on a force plate under stable and unstable (balance pad on top of the force plate) conditions. Performance measures (contact time, jump height, peak ground reaction force) and electromyographic (EMG) activity of leg and trunk muscles were tested in 27 subjects (age 23 +/- A 3 years) during different time intervals (preactivation phase, braking phase, push-off phase).
 The performance of drop jumps under unstable compared to stable conditions produced a decrease in jump height (9 %, p < 0.001, f = 0.92) and an increase in peak ground reaction force (5 %, p = 0.022, f = 0.72), and time for braking phase (12 %, p < 0.001, f = 1.25). When performing drop jumps on unstable compared to stable surfaces, muscle activity was reduced in the lower extremities during the preactivation, braking and push-off phases (11-25 %, p < 0.05, 0.48 a parts per thousand currency sign f a parts per thousand currency sign 1.23). Additionally, when landing on unstable compared to stable conditions, reduced lower limb muscle activities were observed during the preactivation phase (7-60 %, p < 0.05, 0.50 a parts per thousand currency sign f a parts per thousand currency sign 3.62). Trunk muscle activity did not significantly differ between the test conditions for both jumping and landing tasks.
 The present findings indicate that modified feedforward mechanisms in terms of lower leg muscle activities during the preactivation phase and/or possible alterations in leg muscle activity shortly after ground contact (i.e., braking phase) are responsible for performance decrements during jumping on unstable surfaces.
KW  - Stretch-shortening cycle
KW  - Trunk muscle strength
KW  - Jump height
KW  - Electromyography
Y1  - 2013
U6  - https://doi.org/10.1007/s00421-013-2724-6
SN  - 1439-6319
SN  - 1439-6327
VL  - 113
IS  - 12
SP  - 2943
EP  - 2951
PB  - Springer
CY  - New York
ER  -