by Brian McCormick
During a high school all-star training camp last weekend in Los Angeles, Draft Express’ Jonathan Givony tweeted about the players’ inability to hold basic yoga positions. He further blamed these athletes’ weak core strength and commented about his disbelief.
Givony used one of the buzzwords of the training industry: core strength or core stability. There are some basketball trainers who appear to train players strictly for improved core strength (though with no real measure of improved core strength or what it means).
When I spent time at the IMG Academy, I never saw a basketball player perform a power-related lift. Instead, every instruction involved imagining the core or tightening the core or doing something to the core. Givony spends a lot of time watching professional trainers, so I imagine he has picked up on this idea, and its apparent importance to basketball success.
When Givony tweeted about his disbelief, I questioned him. Why should we assume that someone who has likely never performed a yoga pose should be able to perform a pose correctly within seconds or even minutes? If I brought a group of yoga practitioners on the basketball court and asked them to shoot three-pointers, should I be surprised if they were unable to shoot correctly within a few repetitions?
Further, the average elite high school basketball player is growing rapidly which creates a loss of coordination and strength, as the bones grow faster than the muscles. Most fast-growing teenagers illustrate some awkwardness, which is why players such as LeBron James who grew quickly and never appeared to go through the awkward stage are the outliers. Therefore, the inability to execute yoga poses does not equate with a lack of core strength, regardless of one’s definition of core strength, but instead is testament to the skill involved in learning different poses, especially for long-limbed basketball players.
While core strength is the magic elixir of the training world (and not just basketball trainers), another basketball trainer said that he “pukes in his mouth” when a client tells him that he needs core training. This trainer identifies skill deficiencies and the underlying movements of the skills and creates an exercise program that improves these movements and ultimately the skills. While some of the exercises cross over between his training and the core strength trainers’ training, his focus often differs.
When I worked as a personal trainer this summer, I saw many people do a typical abdominal exercise where you do a sit-up and throw a medicine ball. Most people do a full sit-up and throw the ball to their partner or at the wall at the top of the sit-up using mostly the chest and arms to throw the ball; they wait for the ball to rebound to them and then return to the bottom.
When I do this exercise, the entire purpose is different. This is not a sit-up and throw, but an overhead throw from a supine position (lying on one’s back). My focus is not to contract my abdominals for the entirety of the exercise, as I heard several people explain to each other at the gym, but to contract forcefully at the beginning of the movement to initiate the throw. I do not do a full sit-up because I am not doing sit-ups: I am throwing the ball against the wall as forcefully as possible. In the process of throwing the ball, my abdominals contract and my shoulders come off the ground. However, I do not actively contract my abdominals nor do I actively hold the contraction throughout the movement. I use my entire body to throw the ball, not just my chest and arms, and my arms direct the ball rather than supplying the power.
This is an example of an exercise used for core strength by many that is similar to a movement-related exercise used as a tool to teach rapid contraction and relaxation. The best athletes remain relaxed. When Usain Bolt runs, he does not consciously contract and relax his muscles. He does not actively contract his abdominal wall to maintain his posture. He has an amazing ability to contract and relax at the appropriate time and with the proper order of contractions.
When basketball trainers speak about the lack of core strength, they typically point out a flawed movement. They do not measure core strength or stability through a core exercise, like one measures upper body strength with a bench press test or lower body power with a vertical jump test.
The traditional test of core strength is the sit-up test, but this is flawed in several ways. First, a sit-up test tests more for strength endurance than strength or stability. Second, there is no specificity, and therefore no certainty of transfer, between an exercise that occurs lying down involving flexion and stability in a standing posture. Finally, Stuart McGill, the godfather of spine research, says that sit-ups place “devastating loads on the disks.” Other studies have suggested that a front squat activates the core musculature more than a sit-up. So, how does one measure core strength? How does one measure improvement? How much strength does one need?
The Journal of Bodywork and Movement Therapies recently published a critical review titled “The Myth of Core Stability” by Eyal Lederman [Journal of Bodywork & Movement Therapies (2010) 14, 84-98]. Lederman addresses the strength question:
To what force level do the trunk muscles need to co-contract in order to stabilize the spine? It seems that the answer is not very much.
During standing and walking the trunk muscles are minimally activated (Andersson et al., 1996). In standing the deep spinal erectors, psoas and quadratus lumborum are virtually silent! In some subjects there is no detectable EMG activity in these muscles.
As for strengthening the core muscles, he writes:
A recent study has demonstrated that as much as 70% MVC [maximal voluntary contraction] is needed to promote strength gains in abdominal muscle (Stevens et al., 2008). It is unlikely that during CS [core strength] exercise abdominal muscle would reach this force level (Stevens et al., 2007).
So, what should a trainer do when there is a noticeable skill deficiency attributed to lack of trunk stability? For instance, some ACL studies have identified lack of core strength as a precursor to ACL injuries, while others simply appear to lack total body coordination which impedes their ability to stop or even execute skilled movements like shooting or jump stops or to hold their proper defensive stance (posture).
Lederman reminds coaches and trainers to remember the specificity principle of motor learning. He cites a study that “assessed the effect of training on a Swiss ball on core stability muscles and the economy of running...The subjects got very good at using their muscles for sitting on a large inflatable rubber ball but it had no effect on their running performance.”
“Trunk control will change according to the specific activity the subject is practicing. Throwing a ball would require trunk control, which is different to running. Trunk control in running will be different in climbing and so on. There is no one universal exercise for trunk control that would account for the specific needs of all activities. Is it possible to train the trunk control to specific activity? Yes, and it is simple - just train in that activity and don’t worry about the trunk. The beauty of it all is that no matter what activity is carried out the trunk muscles are always specifically exercised.”
If one sees a trunk control problem while doing yoga poses, the athlete needs more practice doing the yoga poses. However, this does not mean that the athlete lacks trunk control when shooting a basketball or making a jump stop. Similarly, if the athlete struggles to execute a jump stop, yoga will not necessarily improve his trunk control on jump stops. Instead, practicing jump stops is more likely to lead to improved performance of jump stops and improved trunk control on jump stops.
As for attacking the core stability through the activity and asking an athlete to concentrate on his core, as many trainers do, would you ask an athlete to have such an internal focus of control when running or lifting weights or shooting a basketball?
Let’s imagine two scenarios where we are teaching a patient to lift a weight from the floor using a squat position. In the first scenario, we can give simple internal-focus advice such as bend your knees, and bring the weight close to your body, etc (van Dieen et al., 1999; Kingma et al., 2004). This type of instruction contains a mixture of external focusing (e.g. keep the object close to your body and between your knees) and internal focus about the body position during lifting. In the second scenario which is akin to CS training approach, the patient is given the following instructions: focus on co-contracting the hamstrings and the quads, gently release the gluteals, let the calf muscles elongate, while simultaneously shortening the tibialis anterior etc. Such complex internal focusing is the essence of CS training, but applied to the trunk muscles. It would be next to impossible for a person to learn simple tasks using such complicated internal-focus approach.
While core strength and core stability are buzzwords and make trainers and scouts sound knowledgable, what does it mean for sports performance? How does one measure the supposed lack of core strength? How does one train a player with poor trunk control? Do exercises on one’s back lead to improved trunk control in an upright position in a dynamic environment?
Stability is important to sports performance. However, stability is not just abdominal exercises. Stability is global: it includes the entire body working together, not a few muscles located around the spine. Isolating these abdominal muscles in training helps one attain a six-pack, but these exercises do not necessarily improve sports performance or trunk control in sports performance.
Instead, if you want to improve trunk control in a jump stop, start at the basics and progress. The basics of a jump stop would eliminate the ball and any pre-jump stop movement. Focus simply on the body stability when landing from a short jump. Next, add the ball, but no prior movement. Then, execute the stationary jump stop while catching the ball. Then, eliminate the ball and add movement before the jump stop. Next, move prior to the jump stop while holding the ball. Finally, return to the full jump stop with prior movement and ball manipulation (dribbling into the jump stop or receiving a pass). This is a simple progression of motor skill development from the simple to the complex, and provides the specificity required to develop trunk control for an activity.