The effects of attentional focus on jump performance and knee joint kinematics in patients after ACL reconstruction

Abstract

Objectives: The purpose of this study was to determine the effect of an internal and external attentional focus on single leg hop jump distance and knee kinematics in patients after ACL reconstruction (ACLR).

Design: Experimental.

Setting: Outpatient physical therapy facility.

Participants: Sixteen patients after ACLR.

Main outcome measures: Patients received either an instruction with an internal focus or an external focus before performing a single leg hop jump. The jump distance, knee valgus angle at initial contact, peak knee valgus angle, knee flexion angle at initial contact, peak knee flexion angle, total ROM and time to peak angles for the injured and non-injured legs were recorded. A repeated measures MANOVA was used to determine significance between the experimental conditions with the primary outcome measures as dependent variables.

Results: The external focus group had significant larger knee flexion angles at initial contact, peak knee flexion, total ROM and time to peak knee flexion for the injured legs.

Conclusions: This study demonstrates the applicability of using an external focus during rehabilitation of patients after ACLR to enhance safer movement patterns compared to an internal focus of attention and subsequently may help to reduce second ACL injury risk.

Keywords: Anterior cruciate ligament; Attentional focus; Kinematics; Motor learning.