Clustering U-14 Portuguese regional team football players by lower limb strength, power, dynamic balance, speed and change of direction: understanding the field position factor
The aim of this study was to cluster U-14 Portuguese regional team
football players based on variables related to lower limb strength and power, dynamic
balance, linear sprint, and change of direction.
Method: The sample consisted of 22 young male soccer players (13.83 ± 0.44 years).
A set of variables related to lower limb strength and power, dynamic balance, linear
sprint, and change of direction was measured.
Results: Overall, a non-significant field position was observed. The
countermovement jump (p < 0.001, η2 = 0.73), squat jump (p < 0.001), and 30 m
linear sprint (p = 0.001) were the main variables responsible for establishing the
clusters. Cluster 1 was characterized by a high slalom, i.e., it took longer to complete
the test (speed and change of direction) and a low composite score in the dynamic
balance. Cluster 2 was characterized by high squat jump, countermovement jump,
and reactive strength ratio (lower limb strength and power). Cluster 3 was
characterized by low squat jump and countermovement jump (lower limb strength
and power), and a high 30 m sprint, i.e., it took longer to complete the test (speed and
change of direction). Based on the results of the territorial map, the clusters consisted
of: (i) cluster 1: two forwards, one midfielder, and five defenders; (ii) cluster 2: three
forwards, two midfielders, and two defenders, and; (iii) cluster 3: four midfielders and
three defenders.
Conclusions: Players from different field positions composed the three clusters.
There was no cluster composed exclusively of players of the same field position.
The development of individualized and specific enrichment training programs
should consider a cluster analysis, as the positional effect can be overlooked.
The authors received funding from the FCT—Portuguese Foundation for Science and
Technology under the project UIBD/DTP/04045/2020. The funders had no role in study
design, data collection and analysis, decision to publish, or preparation of the manuscript. The following grant information was disclosed by the authors:
FCT—Portuguese Foundation for Science and Technology: UIBD/DTP/04045/2020
