Perhaps you’ve seen an online video where a Kung Fu Sifu shows you his technique for rock hard hands, which involves punching a wall. The logic behind this is that micro-fractures occur within the bones, which will become stronger once they heal up.
But you may be wondering the legitimacy of these claims. So does punching walls actually make your knuckles stronger?
Punching walls might in theory make your knuckles stronger, but it is not recommended, as the strength increase is nominal compared to the amount of wear and tear your hands will receive. A better way to strengthen the knuckles is by hitting the heavy bag bare-knuckle, as it is less likely to injure your hands and cause arthritis later in life.
Let’s look at why punching walls might sound like a good idea, and why it really isn’t a good idea.
There are claims that creating micro-fractures in the bone will cause it to heal back stronger. This is a big part of Muay Thai training when it comes to the shin bones. Kicks are a big part of Muay Thai, and practitioners are taught to land their kick with the shin.
In order to make their kicks stronger, Thai fighters will often kick down banana trees, causing small fractures in the shin bones. Through a process known as ‘bone remodeling’, the body replaces mature or fractured bone and replaces it with healthy, strong bone.
This process of bone remodeling happens with all the bones in your body, and is actually an active process, regardless of the condition of your bones. It is possible that these micro-fractures cause the bone to calcify and heal up stronger. However, I could not find a medical study that explicitly confirmed this. Most of the sources saying this are martial arts related, and do not source any studies.
The more likely scenario is that kicking trees numbs the feeling of pain in the shin. This means the bone itself isn’t actually stronger, but simply that the fighter is used to the pain, and simply able to strike with more force. The brutal nature of Muay Thai (and its training methods) is one of the reasons I included it in the post What Is The Best Martial Art For A Street Fight?
The same is likely true for the bones of the hand. Any strength improvement in your bare-knuckle punches is simply from being able to tolerate more pain, and not because the bones are actually stronger.
I remember when I first started training, my knuckles would always hurt, even with gloves and wraps on. Over time, the pain just subsided, likely due to my hands getting used to the stress.
Despite the lack of evidence to suggest that bones are stronger after a micro-fracture, there actually is evidence showing that bones get stronger to adapt to the load placed on them.
This is known as Wolff’s law, where as bones actively rebuild themselves, they also change their formation to resist the load placed upon them. A great example of this is Olympic Weighlifters, who have been shown to have higher bone density than the average person, due to the large amount of weight placed on their skeleton.
According to the American Journal of Physical Anthropology, the weight your bones carry is equally as important in shaping the bones as genetics is. In the abstract, they state, “while there are important genetic influences on bone development and on the nature of bone’s response to mechanical loading, variations in loadings themselves are equally if not more important in determining variations in morphology”.
So what does this mean for your hand bones? Well as far as pain in the hand goes, bone strength will not affect it at all, no matter how many walls you punch. But, bone strength can prevent breaks in the bone, due the changes in its morphology from stress over time.
Hand pain will slowly subside over time, due to both a betterment in your technique and getting used to the pain. Preventing breaks in the bone is more important, so let’s talk about how to form and strengthen them through training.
For starters, training and hitting the bag will place loads on your hands, wrists, and forearms. Simply hitting the bag can strengthen the bones in your hands over time. The Swedish School of Sport and Health Sciences conducted a study comparing hand density between amateur boxers and active people who were non-boxers.
Here is what they found: “Forearm and arm Bone Mineral Density were 1.5-2.2% higher in boxers than the control group”. Unfortunately, I could not find any studies that studied the bones of the hands in particular, as these bones carry just as much (if not more) weight as the forearm.
This study proves that simply training as a boxer would will increase the density of the bones in your hands. There are exercises you can do to place more weight on the hands, such as doing push ups on your knuckles. But over time, simply hitting the heavy bag (both gloved and bare-knuckle) should help you build that bone density.
However, as I note in the post Why Do Boxers And MMA Fighters Wear Gloves?, bones in the hand are very brittle, as they are simply not designed for hitting things. Always wear proper hand protection (such as wraps and gloves) when training your striking.
So when you started reading this post, you probably wanted to start punching some walls. I mean, if it makes my hands harder right? Now that we know punching walls doesn’t make your hands stronger, let’s talk about why you shouldn’t do it anyways.
Of course, there is the most common injury of breaking your hand. This could be the case if you are punching a very sturdy wall at full force. However, most people realize this is a bad idea, and will instead hit the wall more softly, hoping to build up resistance and force over time.
While this process of slowly adding force may not cause your hands to break, it can cause other injuries. The most common hand injury for fighters, aside from breaks and fractures, is a tear in the sagittal band of the knuckle.
This is an injury commonly, known as “boxer’s knuckle”, due to its occurrence among boxers. It can be recognized by the knuckle moving to the side when the hand is closed, and straightening out when the hand is open.
Not much force is needed for the impact of a punch to tear the sagittal band. Many fighters even experience this type of tear through their gloves.
Pain in your hands may seem annoying as you start boxing, but over time, it will subside. The same goes for hand strength. As you continue to box, your hands and wrists will adjust to the force being applied to them, gaining bone density over time.
Punching walls could theoretically improve hand strength by increasing bone density over time, but the chance of breaking your hands is extremely high. A better alternative would be to practice hitting the heavy bag bare knuckle, and increase the force over time.
If you want to know more tips on strength and technique used in martial arts, check out the Training Tips page. Thanks for reading!