Running Head: Guided Article Critique 2
Background
Change of Direction in sport is obviously important and even more so how to attain peak
change of direction. The association of change of direction also has a direct correlation with
power, speed and agility. The article intends to review the validity of strength and plyometric
training’s outcome of change of direction. Change of direction is essentially the definition of
agility. Without the presents of power and strength, particularly in the lower half of the body;
there is no inconceivable way that an athlete could reach peak power and thusly, elite change in
direction, speed and agility. The question of interest was whether performance and muscle
activation in the strength tests could better account for performance and muscle activation in the
force-dominant COD, and vice versa, the plyometric tests and the velocity-dominant COD
(Falch, Rædergård & van den Tillaar, 2020). Strength- and plyometric-training measures are
commonly used to try to improve COD performance. It does this implementing various squat
variations performed bilaterally and unilaterally. These are both the vertical and lateral
directional movements. This includes plyometric, strength training, as well as tests; in which the
article studies the plausibility of these methods, either combined or on an individual basis.
Summary:
When an athlete is undergoing change of direction training, the obvious thing would be to
do focus on the specific thing you want to improve on. Twenty-three football players from the
Norwegian national league were selected. All of these athletes had been training a minimum of
two times a week. Each subject performed a series of COD tests, strength teste, and plyometric
in one test. The article describes strength and plyometric tests will vastly improve your over
COD actions. The COD test consisted of a 45° and 180° turn along with a 4 m and 20 m sprint
approaching the COD, making four runs in total. After the COD test, the strength and plyometric
Running Head: Guided Article Critique 2
exercises were done in a randomized order. The players were given their attempts to do this
event. The exercises that were done in the vertical direction performed bilaterally and
unilaterally. The strength and plyometric tests were done in the same directions. Lateral
movement exercises used were the skate jump and the lateral squat. For unilateral movements
the focus was on jump height. This was basically a vertical jump test or very similar.
In order to get accurate measurements for the events, electric timing gates from Brower
Timing Systems and the jump was recorded with an infrared optical contact grid by Ergotest
innovation. The activity in the muscle was tracked using Electromyography which tracks
electrical signals caused when muscles contract and relax.
Results:
With the data gathered it showed that none of the strength tests linked with COD
performance. Since no major difference in EMG activity was found between COD and
acceleration step for any of the muscles, the top muscle activity of these steps were used and
compared with the different exercises. The only difference in activity was in the soleus and the
adductor longus muscles between the different CODs was found. As for the bilateral squat
exercise, a smaller amount activity was found in most muscles compared with the CODs, except
for the rectus femoris and gluteus maximus. In another article about shot term effects on lower
body functional power development: weight lifting vs vertical jump training programs. It shows
that Olympic lifting exercises produced broader performance progresses than vertical jump
exercises. In addition, training effects due to the vertical jump seemed to be specific to the
training exercises (Tricoli VA, Lamas L, Carnevale R, 2005). If you want to improve on your
vetical jump then you should work on your vertical jump. Weight lifting movements can help
Running Head: Guided Article Critique 2
some but it a more broadened way than specific. It’s basically saying concentrate on what you
want improve and focus on that movement.
Discussion:
The main point of this experiment was to see the relationship between strength and
plyometric tests with force-and velocity-dominant CODs. The other was to compare muscle
activity of the different exercises with CODs. The strength exercises didn’t correlate with COD
performance.
Peak muscle activation of the strength exercises was significantly different compared
with the CODs, for several muscles, while only different muscle activity in the rectus femoris
and gastrocnemius of the plyometric exercises was observed. Furthermore, the plyometric
exercise performances revealed significant correlations with the CODs (Falch, Rædergård & van
den Tillaar, 2020).
Conclusion:
The plyometric tests showed associations with CODs while the strength tests showed
little to no effect. The differences in muscle activation in plyometric exercises are to show more
physical similarities with both strength and velocity CODs compared to strength exercises.
Due to the observed differences in muscle activation, plyometric exercises are indicated
to share more physical similarities with both the strength- and velocity-dominant CODs, in
comparison to the strength exercises in this cohort. The use of unilateral, horizontal, closed chain
Running Head: Guided Article Critique 2
Brughelli, M., Cronin, J., Levin, G., & Chaouachi, A. (2008). Understanding Change of
Direction Ability in Sport. Sports Medicine, 38(12), 1045-1063. doi: 10.2165/00007256-
200838120-00007 Hoffman JR, Ratamess NA, Cooper JJ, et al. Comparison of loaded and
unloaded jump squat training on strength/-power performance in college football players. J
Strength Cond Res 2005; 19 (4): 810-5
Falch, H., Rædergård, H., & van den Tillaar, R. (2020). Association of strength and
plyometric exercises with change of direction performances. PLOS ONE, 15(9), e0238580. doi:
10.1371/journal.pone.0238580
Malisoux L, Francaux M, Nielens H, et al. Stretch-shortening cycle exercises: an
effective training paradigm to enhance power output of human single muscle fibers. J
Appl Physiol 2006; 100 (3): 771-9
Markovic G, Jukic I, Milanovic D, et al. Effects of sprint and plyometric training on
muscle function and athletic performance. J Strength Cond Res 2007; 21 (2): 543-9
Tricoli VA, Lamas L, Carnevale R, et al. Short-term effects on lower-body functional
power development: weightlifting vs vertical jump training programs. J Strength Cond Res 2005;
19 (2): 433-7
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