En forskningsanalyse fra april i år tok for seg arbeidet med å samle store deler av forskningen på muskelaktivering under knebøy, og relevante varianter av beinøvelser.
Clark DR, Lambert MI, Hunter AM. Muscle activation in the loaded free barbell squat: a brief review. J Strength Cond Res. 2012 Apr;26(4):1169-78. Pubmed. Full tekst PDF: 2012 – Muscle activation in the loaded free barbell squat – a brief review.pdf
Det er mye interessant i denne studien, så jeg vil anbefale interesserte å lese den på egenhånd. Her er oppsummeringen:
– «Increasing stance width and hip rotation increase activation of the adductors and gluteus maximus and not the primary movers of the squat exercise.
– Muscle activation is not different in squats to varying depths at moderate loads. Within a parallel squat, it appears that activation is greatest in the last phase of the descent and the first phase of the ascent.
– Activation of the muscles of the legs and trunk increases as a consequence of increases in absolute external load.
– It is important to use equal, relative, submaximal test loads calculated from a maximum for each specific squat if the aim is to measure the differences in activation between 2 types of squat or squat variation such as depth of squat.
– Muscle activity is not influenced by the use of a weight belt.
– Squatting on an unstable base increases the activation of the leg and trunk muscle, but it impairs force and power production in this exercise.
– The squat at moderate external loads is a more effective method of activating the trunk stabilizers compared with other instability trunk exercises.
– Acute fatigue in a submaximal squatting task results in increased muscle activation corresponding to a loss of power across the task. Power and EMG is reduced for up to 30 minutes in a low and high load power test.
– Muscle activation in muscles of the leg, thigh, and trunk is the same in the front and back squat at 70% of 1RM.
– Free bar squat elicits higher overall EMG than squats in a Smith Machine, leg press, and leg extension.
– Highest activation occurs in the concentric phase of the squat.
– In sets to failure at 85% 1RM, trained subjects completed significantly more squat repetitions than untrained subjects and produced higher muscle activation in both the 1RM test and the set of repetitions to failure.»
Spesielt interessant i mine øyne:
- KNEBØY og FRONTBØY gir samme aktivering.
– ‘Stabilitetstrening’ aka. Knebøy på bosu-ball, suger.
Praktiske anbefalinger: Kom deg på gymmet og kjør FRONTBØY! Gå ned til 90 grader eller dypere, og push på med maksimal hastighet på veien opp igjen. Repeter.