The effect of external focus versus internal focus instruction on jump-landing biomechanics in healthy females.

CONTEXT: Different forms of instruction have contributed to favorable results in injury interventions. External focus (EF) instruction may be superior to internal focus (IF) instruction.

OBJECTIVE: To investigate the difference in landing biomechanics between participants who received EF versus IF instruction and a control. A secondary aim was to evaluate participant perceptions of focus of attention.

DESIGN: Randomized controlled trial.

SETTING: Laboratory.

PATIENTS OR OTHER PARTICIPANTS: Forty-one healthy females. EF: N=14; 23.0±2.9yrs; 1.69±0.07m; 64.0±6.8kg; IF: N=15; 22.9±3.2yrs;1.66±0.08m;66.2±12.4kg; Control: N=12; ±2.9yrs; 1.67±0.11m; 74.3±15.1kg.

MAIN OUTCOME MEASURES: Participants scoring ≥ five on the LESS and were allocated into EF, IF or control groups. Knee and hip flexion and abduction were collected pre- and post-intervention during five drop vertical jumps. For the intervention, each group was provided separate instructions. In-between the intervention jumps, participants answered: "What strategy were you focusing on when completing the previous jump-landing trials?". Post-intervention minus pre-intervention change scores were calculated and separate 1-way ANOVAs assessed differences in the dependent variables.

RESULTS: EF had a greater change in hip and knee flexion angles versus control. There was no significant difference between EF and IF for any variables. There were no significant differences in frontal plane variables. In the EF group, 71.4% were "aligned". In the IF group, 80% of the were "aligned". In the CONT group, 50% were "aligned".

CONCLUSIONS: EF instruction may not produce immediate changes in movement compared to IF instruction. Hip and knee flexion were greater in the EF group compared to the control group but was not better than the IF group. Clinicians should provide instruction to patients, but the mode of instruction may not be as critical to see positive biomechanical changes. Patients may not always focus on the instruction being given, therefore the relationship between instruction and patient experience should be further explored.