What is the target organ/system of training? While many think it's the muscular or cardiovascular systems, the true target is the nervous system. The brain exists to move us thru, and interact with, the environment. The sensory input our nervous system receives from interacting with the environment drives the motor output from the brain to the neuromusculoskeletal system. By altering sensory input, we can change and potentially improve neuromotor output. One way to hack the nervous system and increase stability throughout the system is through challenging the grip.
This image is a homunculus (literally meaning "little man") and it is both grotesque and informative - not unlike the founder of this website. It is essentially a representation of the processing regions devoted to each area of the body. The importance here is the tremendous amount of sensory and motor cortex devoted to the hands and feet (more on them in a future post). Our evolution has clearly indicated the importance of sensory input and motor output through the hands given it's large representation in the brain. We know sensory input is absolutely critical in the motor development of kids and those who struggle with sensory integration have some serious movement problems. So why not better utilize sensory input with our training and optimize adaptation?
By challenging the grip and maintaining a fist we provide a rich sensory input to the brain that allows us to produce more stability and a system-wide increase in force output (which is what we really want). The strength of this stimulus probably improves motor learning too. A big grip tells the brain that the position is a stable one and it is safe to generate a lot more force without risk of destabilization and injury.
Don't believe me? Try flexing your biceps without making a fist - it's really hard to generate much of a contraction. Then make a crushing fist while contracting your biceps. The result is a much greater biceps contraction as you are amplifying the motor output of the brain - often called irradiation or overflow. By augmenting the stronger parts of the pattern, we can facilitate improved neuromuscular activation thru the weaker parts.
Seriously, try making a fist as hard as you can - you feel the tension all the way up to the middle of your back as this overflow sets the scapulae and thoracic spine (spinal control is always crucial) allowing a stable platform for power generation by closing the circuit. Pavel has used this for years with the Soviet Special Forces and his Kettlebell training paradigms.
So how do we train grip and hack the system?
1) To initiate grip training I like to start with having the athlete grip the bar, club, or bat way harder than they think they need to. This is important to train initially as it helps to improve a strong grip pattern on demand in order to progress to more dynamic movements when rapid and powerful upper extremity stability is needed.
2) Challenge grip demands by varying the grip width of the bar - wrapping a towel around the bar is probably your cheapest route though you can buy various thick bars if you're sitting on some disposable income. By training the grip we can improve adaptation without adding more load to the system which may aide in recovery and lessen the odds of injury without losing performance (Charlie Weingroff has some great insight on the nervous system as well as minimizing system load).
3) For unilateral and one-arm movements (farmer's carries, kettlebell swings) maintain a strong, closed fist in the non-working hand. This is crucial. By stabilizing the system thru a closed fist the circuit itself is closed, the scapulae and spine are fixated, and increased force is transmitted thru the working arm and not lost via a limp wrist on the non-working hand.
4) Work more with kettlebells. The uneven weight distribution of the bell and the ballistic nature of many kettlebell movements really challenges grip and allows for some serious neural input and adaptation to occur. Kettlebell work really challenges the reflexive component of grip which is crucial for performance - generating a powerful, stabilized arm and torso on demand for maximum efficiency.
The best athletes can create tons of force AND control on demand and grip training is a way to tap into the nervous system and optimize adaptation. The more we can impact and alter the sensory experience the more we can improve movement quality.