Wend-Uwe Boeckh-Behrens Wolfgang Buskies. Fitness-Krafttraining.:
Die besten Übungen und Methoden für Sport und Gesundheit.
Rowohlt, Reinbek bei Hamburg, 2000.
Boeckh-Behrens & Buskies performed a series of research
studies using data as measured by electromyography (10 male
resistance-trained subjects, mean age 22y, mean body-fat 13%) for
all the major and minor muscle groups of the legs. This included:
This article will cover the quadriceps, so here is are the
exercises researchers felt worked best for each quads. See if you
Image 4:Inner (vastus medialis), medial
(vastus intermedius & rectus femo ris) and
outer (vastus lateralis) parts of the "quads"
1. Hack squats, lying on machine,
50° knee angle
Figure 1: Relative EMG activity of all four heads
of the quadriceps during hack squat, leg press, squat and leg
extension variations in comparison to barbell squatting to
parallel (knee angle 75°) data adapted from Boeckh-Behrens
& Buskies. 2000
2. Hack squats, lying on machine, 90° knee angle
3. Squats, barbell, 70° knee angle
4. 45° leg press, 90° knee angle
5. Squats, barbell, 90° knee angle
6. Squats, barbell, 40° knee angle
As you can see from figure 1, there is not really that much
difference between exercises, but when you think about the amount
of sheer stress caused to the patella the difference might be
pretty high as see in figure 2.
Figure 2: Shear and compressive forces during
squat exercise measured at different knee angles expressed as
percentage of the sum of body weight + load (data adapted from
a compilation in Escamilla. 2000)
So is stance or toe angle important to developing different parts
of the quads? (seems like I wrote about this in Muscle and Fitness
Figure 3: Relative EMG activity of the outer part
of the quadriceps (m. vastus lateralis) during barbell squat
and single legged squat variations in comparison to barbell
squatting to 90° knee angle data adapted from Boeckh-Behrens
& Buskies. 2000
Researchers felt that when it comes to training the vastus
medialis (tear drop) a slightly narrower stance may be
advantageous. However, positioning of the feet pointing outward
past at a 30° angle seems to be negligible (+/- 0.25%).
As for the vastus lateralis a maximal squats even to above
parallel (70 degrees) is great. It seems that even with lighter
weight, going below parallel starts deactivating the lateralis.
Single leg exercise work the same way.
How about the medial part of the quads which include the vastus
intermedius and rectus femoris?
: Relative EMG activity of the medial part of
the quadriceps (vastus intermedius & rectus femoris)
during selected exercises in comparison to hack squats to a
50° knee angle data adapted from Boeckh-Behrens & Buskies.
According to the data hack squat and the leg press are among the
most effective exercises for the medial part of the quads. Again,
angle seems to be important for results and joint safety so a 50
degree hack squat and 90 degree leg press seem to be optimal. If
you are into doing cable exercises the leg kick with the cable
attacked to the ankle might be an even better option, to develop
the rectus femoris. Which makes sense, because this muscle also
works as an extensor. This exercise is done just like you are
kicking a football.