Crown Your Lower Body With Squats, the King of Thigh Builders

By Stephen E. Alway, Ph.D., FACSM

The evolution of modern gyms from free weights to machines has created a paradox. On one hand, the machines allow one to move quickly and efficiently from one exercise to another without having to break down or add plates to a bar. However, excessive use of machines, especially for the lower body, robs the lifter of a structural base for power and strength, which can best be established by multi-joint and multi-muscle activation. Enter the barbell squat, which arguably presents the best strategy for capturing lower body supremacy. Not only can squats add to the size and strength of the anterior thigh muscles, but this multifaceted exercise also activates the gluteal muscles, smaller hip muscles, lower and middle back, hamstrings, and even the calves. While it is king of lower body exercises, rising to this status comes with a price. That price is paid via gut-busting effort, but success in barbell squats is certainly to spread to success throughout the entire body.

Muscle Structure and Function

Even though the squat involves many muscles, space limitations permit only a focus on the quadriceps femoris muscle group of the anterior thigh. The quadriceps femoris (“quads”) consists of four muscles. Three of these muscles are connected to, and positioned over, the lateral (vastus lateralis), medial (vastus medialis), or middle sections (vastus intermedius) of the anterior (front) part of the femur bone of the thigh. The rectus femoris (rectus=straight) is the fourth muscle in the quadriceps group. Unlike the vasti muscles, it begins on the hipbones at the iliac crest and above the socket where the head of the femur sits (acetabulum) in the hip. The fibers of the rectus femoris run straight down from the hip to the knee. The tendon from the vastus lateralis muscle combines with the tendons from the other two vasti muscles and the tendon of the rectus femoris to form the quadriceps tendon. The quadriceps tendon attaches to the patella (kneecap) and continues inferiorly (towards the foot) from the patella, where it is called the patellar ligament. The patellar ligament inserts into the tibial tuberosity, a bumpy portion on the tibia bone of the lower leg. Together, the three vasti muscles and the rectus femoris muscle form the only structures that extend the leg at the knee (straighten the knee). The rectus femoris is much weaker when the hip is flexed (e.g., seated position such as doing leg extensions) but is a strong contributor during the top portion of the squat. The three vastus muscles are strongly activated throughout the barbell squat to parallel.

Barbell squats to parallel

1. Place your Olympic squat bar on a power rack so that it is at mid chest level when you are facing it. Warm your knees up with lighter weights in the early sets and save the heavy stuff for the final three or four sets. Set the height of the lower safety bar of the power rack about two inches lower than the bottom position of your squat.

2. Most gyms will have a bar pad that you can wrap around the middle sections of the bar before setting up for the squat. Alternatively, you can wrap the center of the bar with a towel or place the towel across your upper trapezius so the bar will rest on the towel.

3. Grip the bar firmly with a wide grip using a pronated grip (palms away from your face). Place your head under the bar and bend your knees slightly. Position the bar high across the shoulders and the upper trapezius muscles (but not on your neck).

4. Place your feet shoulder width apart. Lift the bar from its starting position on the power rack (do not jerk the bar) by extending (straightening) the knees.

5. Take one step backwards, just enough to clear the upper rack supports, so that you will not hit it during the exercise. Place your feet a little wider than shoulder width, with the toes pointed slightly outward to improve your base of support. Keep your head up and your back straight and tight but maintain its natural curves.

6. Control the weight as you slowly lower your buttocks towards the floor. Continue squatting downward until the tops of your thighs are parallel to the floor or when your knee angle has reached 90 degrees. Do not go below this position.

7. After you have reached the parallel position, stand up in a forceful but smooth movement. Stop just short of fully locking out the knees, thereby maintaining the tension on the anterior thigh muscles. Keep your back tight and flat and your head up both on the way up and on the way down.

All four quadriceps muscles are strongly activated during the ascent. However, the relative degree of muscle activity differs among these muscles. The tension in the vasti muscles diminishes as you approach the top portion of the lift. Conversely, the rectus femoris is less active at the bottom, but it is strongly activated near the top one-third of the movement. The gluteus maximus and hamstring muscles are strong extensors of the hip and therefore they are active during the ascent of the squat. The erector spinae muscles achieve a moderate isometric contraction during the lift to keep the back flat.

There is a misconception that success occurs only if you are only able to crawl out of the gym after a squat day. However, this philosophy is usually developed from improper exercise form (e.g., bending forward, lifting too much weight sloppily, etc.). Sure, you must train heavy, but you must also feel the weight and concentrate on your quadriceps during the exercise. The goal is not to invoke quadriceps suicide, but rather to activate the quadriceps fully, then let them grow and strengthen. Proper and careful use of the barbell squat to parallel will crown your lower body metamorphosis from average to supreme.

References:

Bentley JR, Amonette WE, De Witt JK and Hagan RD. Effects of different lifting cadences on ground reaction forces during the squat exercise. J Strength Cond Res 24: 1414-1420, 2010.
Brandon R, Howatson G and Hunter A. Reliability of a combined biomechanical and surface electromyographical analysis system during dynamic barbell squat exercise. J Sports Sci 29: 1389-1397, 2011.
Ebben WP, Kaufmann CE, Fauth ML and Petushek EJ. Kinetic analysis of concurrent activation potentiation during back squats and jump squats. J Strength Cond Res 24: 1515-1519, 2010.
McBride JM, Haines TL and Kirby TJ. Effect of loading on peak power of the bar, body, and system during power cleans, squats, and jump squats. J Sports Sci 29: 1215-1221, 2011.
Moore, KL and AF Dalley. Clinically oriented Anatomy. Fourth edition. Baltimore, Lippincott Williams & Williams, 531-546, 1999.
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Illustrations by William P. Hamilton, CMI

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