Assessing the Magnitude and Direction of Asymmetry in Unilateral Jump and Change of Direction Speed Tasks in Youth Female Team-Sport Athletes

Abstract

The direction of inter-limb asymmetries and the change of direction (COD) deficit are two aspects that have increased in recent years. The main objective of the present study was to assess the magnitude of neuromuscular asymmetries in an elite youth female team-sports sample and determine its directionality. Secondary objectives were to evaluate the relationship between COD deficit, linear speed and COD time performance. Elite female youth basketball and handball players (n = 33, age = 16 ± 1.17 y) performed the Single Leg Countermovement Jump in vertical (SLCJ-V), horizontal (SLCJ-H), and lateral (SLCJ-L) directions, the COD and the 10-m sprint. Results showed statistical differences between limbs in all the neuromuscular tests (p < 0.001). The Kappa coefficient showed poor to fair levels of agreement between tasks (K range = -0.087 to 0.233), indicating that asymmetries rarely favoured the same limb between skills. Additionally, small and non-significant correlations were found between the linear sprint capacity and the COD ability. The findings of the present study highlight the independent directionality of asymmetries across tests. The COD deficit does not appear to be much more advantageous than COD total time to measure asymmetry. Practitioners are encouraged to use a fitness testing battery to detect existing side differences and each ability should be specifically trained with functional tasks.

Ground Reaction Forces, Asymmetries and Performance of Change of Direction Tasks in Youth Elite Female Basketball Players

“…The findings of the present study are in agreement with previous research highlighting the presence of inter-limb asymmetry in youth elite female basketball players when performing COD tasks [ 36 , 37 ]. In both the COD 180° and COD 70° tests, significant differences were observed between HPL and LPL across all variables.…”

Relationship between Performance and Inter-Limb Asymmetries Using Flywheel Resistance Device in Elite Youth Female Basketball Players

“…This was similar to previous research from Madruga-Parera et al [ 41 ], who identified minimal agreement for side consistency among jump tests (−0.05 to 0.15), or research from Bishop et al [ 15 ], who identified minimal agreement for side consistency in peak force in the SLC-J and single-leg broad jump. As such, these results emphasize the heterogeneity of asymmetry among tests and highlight the need for a more individual approach to data analysis [ 7 , 41 , 42 ].…”

Effect of a High-Intensity Handball-Specific Fatigue Protocol Focused on the Leg Contralateral to the Throwing Arm on Interlimb Asymmetries

“…However, although these results confirm that our protocol was effective to induce lower-body neuromuscular fatigue, it should be kept in mind that the main novelty of our study is that we tried to elucidate whether fatigue could be more intensively manifested in the leg that was more actively involved in the fatigue protocol. This information is of practical importance due to the marked unilateral nature of most high-intensity actions performed in handball as well as in other team sports (1,12,14,33). To simulate the unilateral demands of handball, in this study, the subjects were always instructed to perform the 180°change of direction and the jump preceding the throw with the same leg (i.e., leg contralateral to the throwing arm).…”

“…The high physical demands of handball are expected to lead to fatigue, which could be at least partially responsible for the reduction in the quantity and quality of highintensity actions at the end compared with the beginning of a handball match (31,35). It is also noteworthy that most highintensity actions performed in handball, such as changes of direction and jumps, are mostly performed unilaterally (1,12). Of even more importance could be that, due to the nature of the game, these actions are almost always performed with the same limb (34).…”