Reliability and validity of a wall slide test for monitoring growth-related lower limb pain in elite youth footballers.

OBJECTIVES

To develop and evaluate the reliability and validity of a novel Wall Slide Test for monitoring pain and knee flexion in youth athletes with growth-related lower-limb pathologies.

DESIGN

Reliability and prospective longitudinal cohort study.

SETTING

A Category 1 English Premier League football academy.

PARTICIPANTS

Eighty-one male academy footballers aged 9-17 years with clinically diagnosed lower-limb pain conditions (including Osgood-Schlatter disease, patellofemoral joint pain, Sinding-Larsen-Johansson syndrome, and Sever's disease) and 45 asymptomatic controls.

MAIN OUTCOME MEASURES: Pain at onset of loaded knee flexion (0-10 numerical rating scale), knee flexion range (cm), and a composite Wall Slide Test score. Reliability was assessed using intraclass correlation coefficients (ICC), standard error of measurement (SEM), and minimum detectable change (MDC). Validity was evaluated using mixed-effects models and receiver operating characteristic (ROC) analysis.

RESULTS

Within-day reliability was excellent (ICC = 0.96-0.97). MDC values indicated meaningful detectable change (pain 0.74 points; range 9.1 cm). The composite score demonstrated good to excellent discriminative ability between symptomatic and asymptomatic players (AUC = 0.81-0.94).

CONCLUSIONS

The Wall Slide Test is a simple, reliable, and valid field-based tool for monitoring pain and functional knee flexion in youth athletes, supporting clinical decision-making and longitudinal management.