Abstract
CONTEXT: A quadriceps setting exercise is commonly used following knee injury, but there is great variation in cues that clinicians provide to patients when performing the exercise. OBJECTIVES: To determine if internal, external, or visual cues result in the greatest quadriceps electromyographical (EMG) activity during a quadriceps setting exercise in healthy individuals. DESIGN: Descriptive laboratory study. SETTING: University research laboratory. PATIENTS OR OTHER PARTICIPANTS: Thirty healthy individuals volunteered for this study. Participants were given 1 of 5 cues in a randomized order: internal cue "tighten your thigh muscles," internal cue "push your knee down," external cue "push into the bolster," external cue "push into the strap," or visual biofeedback using the cue "raise the value on the screen as high as you can." MAIN OUTCOME MEASURE(S): Normalized vastus lateralis electromyographical activity. RESULTS: Both visual biofeedback (83.2% ± 24.9%) and the press into the strap condition (76.8% ± 24.4%) produced significantly greater (P < .001) electromyographical activity than the push knee down (53.2% ± 27.0%), tighten thigh (52.7% ± 27.3%), or push into the bolster (50.8% ± 26.3%) conditions. There was no significant difference (P = .10) between the visual biofeedback and press into the strap conditions as well as no significant difference (P > .38) between the push knee down, tighten thigh, or push into the bolster conditions. CONCLUSION: If the clinical aim during a quadriceps setting exercise is to obtain the greatest volitional muscle recruitment, the use of visual biofeedback or pressing into a strap is recommended.