The Anatomy of Grip Strength
Grip strength is the key to creating and demonstrating force. Remember if you can’t grip it, you can’t lift it. This ain’t a science class, but there are some important body parts involved here.
Getting a maniacally strong grip that could bend rebar is pretty straightforward once you understand the anatomy and types of grip strength involved. As a refresher, grip strength is broken down into crushing, pinching, and whole hand or supporting.
The Muscles Used in Grip Strength
Your grip power stems from several key muscle groups in the forearms and hands:
Forearm & Hand Flexors - These muscles on the palm-side of your forearm allow you to curl the fingers and flex the wrist. They include the flexor digitorum superficialis and profundus which bend the fingers, and the flexor pollicis longus which flexes the thumb.
Forearm Extensors - Opposing the flexors, the extensor muscles like the extensor digitorum allow you to straighten and extend the fingers and wrist. They play a key role in support grip.
Thenar Muscles - These smaller thumb muscles like the abductor pollicis brevis and opponens pollicis control thumb movement and opposition to the fingers. This is crucial for pinch grip.
Intrinsic Hand Muscles - Muscles like the lumbrical, interossei and thenar allow for fine motor control of the fingers and hands to form a solid grip.
All of these muscle groups work in concert to produce maximal grip strength from different angles. But training them individually is key. Here’s a breakdown by the style of grip.
Crushing Grip
Your crush grip contains the muscles responsible for that bone-crushing handshake and vise-like closure of the hand. The main players here are the flexor digitorum muscles which bend the fingers, along with the flexor pollicis longus for thumb flexion.
Grippers, thick bar training, and rolling handle lifts are all great crush grip exercises. They pummel those flexors into oblivion.
Pinching Grip
Pinch grip is all about the opposition and coordination of the fingers, particularly the thumb muscles. The thenar muscles like the abductor pollicis brevis which pulls the thumb toward the hand, and the opponens pollicis which enables thumb opposition to the fingers, are hugely involved.
Top pinch grip movements are plate pinches, hub lifts, and block style lifts. Rock climbers and grapplers especially need a monster pinch grip to hold onto things, and not let go.
Support Grip
While crush and pinch grip involve more isolated hand muscles, support grip is about hanging on and using the entire forearm musculature to grasp an object. The flexors, extensors, and intrinsic hand muscles all contribute here.
Pullup hangs, farmer's walks, and resin-style grip holds hammer that support grip like nothing else. Just holding a pull-up for 30+ seconds can expose any weakness in your support grip.
Beyond the Forearm Muscles
Grip can often go beyond just the muscles of the hand and forearm. For instance in a farmer's carry your Trapezius is going to be hammered as well. It’s important to keep in mind that while we’ve gone over the anatomy of primary grip, your other muscles are largely involved in holding on to things. It just so happens the forearm and hands are the weak point as they contain less supporting musculature mass.
The Importance of Powerful Grip Strength Muscles
This should give a nice overview of the muscles involved in grip. We want to emphasize that grip has many separate muscles working together in unison. The point isn’t to memorize every single anatomical term, but to realize that there are many muscles at work here. They all need to be worked with various methods and implements to truly develop your grip.
While you may choose to emphasize one grip area based on your sport or goals, purposeful overall grip training is a worthy pursuit. Mix up your crush, pinch and support work and you'll develop the vise-like hand strength required to move maximum weights and hold on to anything you please.