Análisis cinemático del complejo lumbopélvico y su relación con el miembro inferior

Abstract

Background A risk factor for injury to the lower extremities, specifically the knee, may be a consequence of poor lumbopelvic control affecting kinematics and muscle activity (Fadaei Dehcheshmeh et al., 2021). In turn, carrying out loadbearing activities produces alterations in the mechanics of the foot, and these can affect movement patterns of the proximal joints (Powers, 2003). An example of this is the pronation of the foot, this can produce a medial displacement of the knee during a closed kinetic chain task, such as the single leg squat (SLS) (Telarolli et al., 2020). Objective The main objective of this doctoral thesis was to analyze the relationship of the lumbopelvic complex with the lower limb through different assessment systems. Methodology This doctoral thesis is presented as a compendium of three previously published works. For this, three experimental phases were developed. Firstly, a descriptive study was carried out with a sample of 33 active students, in which the reliability of a smartphone application, OCTOcore, was investigated during the performance of two dynamic tests of the lumbopelvic complex; bird-dog (BD) and single leg deadlift (SLD). In the second study with a sample of 20 students, the relationship between two dynamic assessments of the lumbopelvic complex (BD and SLD) and dynamic knee valgus (DKV) during SLS was studied. And, finally, with a sample of 55 subjects, the reliability of the evaluation of ankle displacement in the frontal plane during the SLS (SLSankle) was investigated by means of a visual observation method, as well as the relationship between the evaluation of the control of the ankle and the degree of pronation of the subtalar joint by means of the navicular drop test (ND). Results In the first study, to obtain the reliability of the test, the intraclass correlation coefficient (ICC) was investigated, whose results are between 0.73 and 0.96, with low variation (0.9% to 4.8%) between days of assessments. Standard error of measurement (SEM) and minimum detectable change difference (CMD) were calculated to study clinical applicability, showing SEM (0.6 to 1.5 mm/s-2) and CMD (2.1 to 3.5mm/s-2). In the second study, a two-dimensional (2D) assessment was performed during SLS to quantify the frontal plane angle of the hip (HFASLS) and the frontal plane angle of the knee (FPPASLS). Ankle dorsiflexion was evaluated using the lunge test, which measures load-bearing dorsiflexion. HFASLS was significantly related to single leg deadlift (r = 0.314, p < 0.05) and ankle dorsiflexion (r= 0.322, p < 0.05). The results showed a significant difference (p < 0.05) during the assessment of central stability (CS), during the SLS, between the cases categorized as dynamic knee valgus (> 10°) and normal (≤ 10°). In the third study, a good intra-rater and inter-rater agreement was obtained during SLSankle, with Kappa values from 0.731 to 0.750. The relationship between SLSankle and ND was significant and Spearman's rank correlation coefficient was 0.504 (p < 0.05). Conclusion To assess the stability of the lumbopelvic complex, the OCTOcore application has been shown to be a reliable tool during the performance of two dynamic exercises, the SLD and the BD. The SLD test is an easyly test to performed during daily clinical practice to assess CD with the OCTOcore app, in physically active women with dynamic knee valgus. The link between core stability and kinematic factors related to knee injuries was measured during the performance of the SLD test, but not in the BD. On the other hand, the central stability deficit may influence the neuromuscular control of the lumbopelvic complex during single-leg movements. Using the SLS to assess ankle displacement provides a reliable alternative to quantify foot mobility compared to the ND. A poor score on the SLSankle test has been shown to be associated with greater pronation on the ND test. For this reason, different professionals are recommended to include the assessment of dynamic central stability, using the OCTOcore application, as well as the assessment of the foot during SLS, to prevent or reduce the risk of injury to the lower extremities during exercises in closed kinetics chain.