Performance in dynamic movement tasks and occurrence of low back pain in youth floorball and basketball players

BACKGROUND

Prospective studies investigating risk factors for low back pain (LBP) in youth athletes are limited. The aim of this prospective study was to investigate the association between hip-pelvic kinematics and vertical ground reaction force (vGRF) during landing tasks and LBP in youth floorball and basketball players.

METHODS

Three-hundred-and-eighty-three Finnish youth female and male floorball and basketball players (mean age 15.7 ± 1.8) participated and were followed up on for 3 years. At the beginning of every study year the players were tested with a single-leg vertical drop jump (SLVDJ) and a vertical drop jump (VDJ). Hip-pelvic kinematics, measured as femur-pelvic angle (FPA) during SLVDJ landing, and peak vGRF and side-to-side asymmetry of vGRF during VDJ landing were the investigated risk factors. Individual exposure time and LBP resulting in time-loss were recorded during the follow-up. Cox's proportional hazard models with mixed effects and time-varying risk factors were used for analysis.

RESULTS

We found an increase in the risk for LBP in players with decreased FPA during SLVDJ landing. There was a small increase in risk for LBP with a one-degree decrease in right leg FPA during SLVDJ landing (HR 1.09, 95% CI 1.02 to 1.17, per one-degree decrease of FPA). Our results showed no significant relationship between risk for LBP and left leg FPA (HR 1.04, 95% CI 0.97 to 1.11, per one-degree decrease of FPA), vGRF (HR 1.83, 95% CI 0.95 to 3.51) or vGRF side-to-side difference (HR 1.22, 95% CI 0.65 to 2.27) during landing tasks.

CONCLUSIONS

Our results suggest that there is an association between hip-pelvic kinematics and future LBP. However, we did not find an association between LBP and vGRF. In the future, the association between hip-pelvic kinematics and LBP occurrence should be investigated further with cohort and intervention studies to verify the results from this investigation.

LEVEL OF EVIDENCE

Prognosis, level 1b.

[An echocardiographic study of patients with left bundle branch block]

24 patients (19 females and 5 males) between 45 and 81 years of age (average age 61.6) with chronic left bundle branch block and with no signs of reduced left ventricular function have been studied by M-Mode echocardiography. These patients have been split into three groups: A) pts. with normal indexes of left ventricular function and normal thickness of the left ventricular walls; B) pts. with normal indexes of left ventricular function and thickness of the interventricular septum at upper limits or increased; C) pts. with different cardiac pathologies but with no signs of reduced ventricular function. The contractility indexes and the motion of the interventricular septum in both the basal and the medial portion have been studied. The results did not show any important variation concerning the ventricular function compared to the normal values. The study of the septal motion pointed out, as a main feature of the left bundle branch block, a preejective posterior motion followed by: a) a normal posterior systolic motion of the interventricular septum, or b) a posterior systolic motion followed by a further posterior protodiastolic motion (delayed motion), or c) an anterior systolic and posterior diastolic motion (paradoxical motion). The alterations of the septal movement ranked in different degrees. The clearest alterations were peculiarly found in the patients of the first group. The patiens of the third group, besides, have shown the lightest alterations. The results allowed to deduce that patients with left bundle branch block can have both normal motion or alterations of the interventricular septum motion of different degree.(ABSTRACT TRUNCATED AT 250 WORDS)