The concept of Points of Flexion training has been around for decades, first credited to Arnold (no last name needed) in the 1970’s. So what is Points of Flexion? Points of Flexion is the concept of training a muscle in all three of its anatomical positions: stretched, mid-range, and shortened. If we examine the biceps in closer detail there are three very common exercises that demonstrate the points of flexion concept: 1) incline curl (stretched position), 2) standing curls (mid-range), 3) Scott Curls aka Preacher Curls (shortened position). The advantage of this concept is two-fold: 1) using different angles changes the strength curve, targeting different aspects of the muscle, 2) using these different angles also changes the emphasis of the muscles being used at the time.
When using the incline curl, more specifically, when the elbows are behind the body, the long head of the biceps are recruited more. As the angle on the bench gets lower (closer to flat) the long head is recruited even more preferentially. Using a neutral grip on the incline curl also increases the recruitment of the long head.
To work the mid-range position, the standing or seated curl variation work both the long head and short head equally. Seated Curls have shown higher EMG activity in the biceps than standing due to the nature of our bodies effectively mitigating stress in a standing position.
The Scott Curl, also known as the Preacher Curl, places the elbows in front of the body. This places the short head of the biceps in a stretched position, emphasizing recruitment of the short head. As shown in the picture, the bench pad on Scott Curls is angled. The flatter the angle on the arm pad the more recruitment we’ll get out of the short head.
Incorporating Point of Flexion into your training program is easy! There two simple ways to incorporate this: 1) using a variation of each angle in one workout, or 2) pick one position, and only vary the angle in each phase. Here’s an example for you to try:
A1: 40 degree Incline Curl – DB – Supinated grip; 4x6-8, 4010, 10s Rest
A2: Seated Curl – DB – Supinated Grip; 4x 6-8, 3010; 10s Rest
A3: Scott Curl – EZ Bar – narrow, supinated grip; 4x 6-8, 4010, 120s Rest
Images Courtesy of Devalier, Frederic (2010). Strength Training Anatomy.