The way a person grips a weight or bar during exercise significantly impacts which muscles are primarily engaged. In strength training, grip terminology describes the orientation of the hands, which dictates the angle of the forearm and elbow joints. The supinated grip, often called the underhand grip, is a fundamental hand position where the palms face the body or upward toward the ceiling. This positioning is used to alter the muscular focus of a movement.
Visual and Technical Definition of Supination
The supinated position is defined by the anatomical movement of the forearm bones, the radius and the ulna. During supination, the radius rotates around the ulna, resulting in the palm turning upward or forward from the body’s anatomical position. When holding a fixed object like a barbell, this rotation places the palms facing the lifter’s torso (if standing) or facing the ceiling (if lying down). This is why the supinated grip is commonly known as the underhand grip.
To maintain a secure and effective supinated grip, the wrist should be kept in a neutral or slightly extended position, avoiding excessive flexion. This positioning ensures that the tension from the weight is effectively transferred to the target muscles rather than being absorbed by the wrist joint. The supinated grip is frequently used with barbells, dumbbells, and pull-up bars.
How Supination Changes Muscle Activation
The functional benefit of using a supinated grip is the mechanically advantageous position it creates for the biceps brachii muscle. The biceps crosses both the elbow and the shoulder joint, making it a powerful supinator of the forearm and an elbow flexor. By forcing the forearm into supination, this grip maximizes the involvement of the biceps, making it the primary muscle for elbow flexion movements.
This hand orientation shifts the workload away from other elbow flexors, such as the brachialis and the brachioradialis, which are more active in neutral or pronated positions. For instance, when performing chin-ups, the supinated grip makes the exercise significantly more biceps-focused compared to a standard overhand pull-up. This targeted activation makes the supinated grip the default choice for accessory movements designed to isolate the biceps, such as barbell curls.
Key Differences from Pronated and Neutral Grips
The supinated grip is one of three primary grip orientations, each defined by the rotation of the forearm. The pronated grip, or overhand grip, is the opposite, with the palms facing away from the body and the knuckles facing upward. This pronated position is used for pulling movements like pull-ups and rows when the goal is to emphasize larger back muscles, such as the latissimus dorsi and rhomboids.
The third primary option is the neutral grip, sometimes called the hammer grip, where the palms face each other. This position is a middle ground that can reduce stress on the shoulder joint and often emphasizes the brachialis and the long head of the biceps. A fourth variation, the mixed grip, combines one supinated hand and one pronated hand. The mixed grip is used almost exclusively in heavy lifts like the deadlift to prevent the bar from rolling out of the hands and enhance grip stability.