Tyler Robbins Fitness

B.Sc. Biochemistry, Certified Strength and Conditioning Specialist (CSCS), Certified CrossFit Trainer (CCFT/CF-L3), USA Weightlifting Level 1

Filtering by Tag: physiology

Learn all about your quadriceps

Source: http://en.wikipedia.org/wiki/Quadriceps_femoris_muscle

Source: http://en.wikipedia.org/wiki/Quadriceps_femoris_muscle

The quadriceps, or "quads", make up majority of the muscle of the anterior portion of the upper leg. The name quadriceps comes from the fact that there are 4 portions or "heads" that make up the quads.

The four heads of the quadriceps are:

  1. Rectus femoris (at right, in blue)
  2. Vastus Lateralis (at right, in yellow)
  3. Vastus Medialis (at right, in red)
  4. Vastus Intermedius (at right, in green)

The Rectus Femoris attaches on the ilium (hip) and covers most of the other 3 heads. The Vastus Lateralis, Medius, and Intermedius all originate on the upper part of the femur. All 4 heads insert, or attach, on the tibial tuberosity just below the knee.

All 4 heads of the quadriceps extend the lower leg at the knee, however, since the rectus femoris is the only head that attaches to the hip, it is the only head that works on flexing the upper leg at the hip.


  • Knee Extension
  • Hip Flexion (rectus femoris only)

Hip Flexion

Knee Extension

Knee Cap


Have you ever thought about why you have a knee cap, also known as the patella? It is a bit odd if you think about it. Your knee cap is, essentially, a free-floating disc of bone. The truth of the matter, however, is that the knee cap is a very important and beneficial tool to improve the effectiveness of the quadriceps.

The quadriceps muscles make up the patella tendon, that passes over the kneecap and attaches to the tibia, just below the knee. Since the tendon passes over the patella (kneecap), when the quadricep muscle pulls on the tibia to extend the leg at the knee, the patella increases the mechanical advantage of the knee.

If you think back to your basic physics lessons in school, the further the generating force (patella tendon) is from the centre of rotation (the knee itself), the less force is required to move the object. This is the same applied principle when using a lever arm. If you were to lift a heavy object, such as a piece of furniture using a lever, the longer the lever, the easier (less overall force) it would be to move said object.

Learn all about your triceps

Source: http://en.wikipedia.org/wiki/Triceps_brachii_muscle

Source: http://en.wikipedia.org/wiki/Triceps_brachii_muscle

There are three heads to the triceps brachii muscle: the medial head (pictured at right in green), the lateral head (pictured at right in yellow), and the long head (pictured at right in red). The long head originates at the scapula whereas both the medial and lateral heads originate on the humerus. All three heads insert or attaches to/on the ulna (forearm).


All three heads act on the forearm by extending (increasing joint angle) at the elbow. This is essentially the primary function of the medial and lateral heads. The long head, however, since it originates on the scapula also helps the shoulder to:

  • Adduct (moving arm towards body or midline)
  • Extend

By knowing and understanding exactly what the biceps do, you can then target them more effectively!

Elbow Extension

Shoulder Abduction (arm away from body)/Adduction (arm towards body)

Shoulder Extension

My Favourite Triceps Exercises

Although the long head is comprised of both main types of muscle fibers, the medial head is primarily made up of small type I fibers (“slow twitch” muscle fibers, which are used in lower intensity exercises. These fibers are involved in muscular endurance/high rep training), and the lateral head is predominantly made up of large type IIb fiber types (“fast twitch” muscle fibers, which are used during high intensity exercise. This fiber type is involved in high force, power, and speed generation).

Knowing this, to fully train your triceps, one should incorporate both low-rep, highly intense loads along with higher-rep, less intense loads. Because of the nature of the triceps, I believe that heavy loads should be handled only through compound movements such as pressing movements utilizing either the chest or shoulders (bench press, overhead press, etc.).

Many of my favourite triceps exercises can be found in my free workouts "The Armoury" and "Triple Threat."

Day 365 - A Year's Worth of Blogs

Well, a year ago today, I set out with this crazy goal/mission to post a blog every single day for 365 straight days. Today, marks the successful completion of said goal with my 365th straight blog!

Read More