The relationship between knee joint angle and knee flexor and extensor muscle strength.
Misook Ha, Dongwook Han
PMID 28533606WHAT IT FOUND
Knee extension strength was higher at 67° than at 25° in female students.
Knee flexion strength was higher at 25°, but the right side did not differ. Angle changes which muscle action is strongest.
Key findings
01Maximum knee extension strength was reported as larger at 67° than at 25° on both sides with p<0.05, with right values of 55.7 and 94.6 and left values of 66.0 and 101.5.
02Maximum knee flexion strength was reported as larger at 25° than at 67° on the left side (56.3 and 42.7) with a statistical difference, while the right side (54.6 and 41.5) showed no statistical difference.
03Average strength showed the same direction: extension was larger at 67° and flexion was larger at 25° on both sides with p<0.05.
STILL TO COME
How it was doneWhat they foundWhat it means for PTs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
The paper did not report how many female students were tested. It tested only two knee angles, 25° and 67°, so it cannot identify the best angle. The participants were healthy female students with no lower-limb disability, so results may not apply to patients with knee pain, weakness or neurological problems. The study measured strength values only; it did not test training, function, pain or patient outcomes. The text reports a significant left extension difference, while Table 1 does not mark left extension with the same asterisk, so the significance reporting is not fully clear.
The easy way to misread this
Do not conclude that 67° is the best knee angle for all training or that these strength values show a training benefit. The study measured only two angles in healthy female students, did not report the sample size, and found flexion strength larger at 25°.