A majority of popular fitness plans continue to include motions that require the participant to apply force while simultaneously loading the spine. This is dangerous as the stress on the spine is amplified by the amount of flexion versus how much weight is loaded to the structures of the back.
Before we talk about the risks of flexion-based exercises, however, let’s cover the basic physics and material science that play a role with the human body.
First, let’s use the foundation of a building as an example of how the spine serves its role in the body. For the most part, a building’s foundation is ridged. It has to be able to resist and distribute large amounts of weight evenly to prevent the structure from collapsing. The more motion that is introduced to the foundation, the greater the chance of a structural collapse. There is only a limited amount of motion that the foundation can tolerate before a catastrophic failure occurs. A foundation that is built with more motion in mind is going to reduce the amount of load that it can safely hold.
When it comes to the body’s foundation, the spine not only has to hold and distribute load but also provide mobility. The body relies on muscles to help redistribute the load safely across the spine. As long as the load stays below the minimum tolerance of the muscles, the body should be able to avoid injury. Unfortunately, as the muscles fatigue or become overused, their effectiveness to redistribute the load safely and maintain mobility is compromised, resulting in excess motion and possible injury.
Poor lifting and squat mechanics are a leading cause of injuries in gyms. A majority of healthy individuals can sustain up to 2,600 to 3,300 pounds of force around the spine safely. This does not mean the spine can take the force of a 2,600-pound squat or deadlift. These are the forces exerted on the discs. A bare spine (structure only, no muscles) is able to withstand only about 4.7 pounds. Without muscles, the spine would collapse under the weight of the head. Even the simple act of walking causes 2.5 times the body weight of force through the back.
For example, the force from an average sit-up is roughly 746 pounds of pressure. If you were to hold a 59.5 lbs. box or weight in front of you and squat, the compressive forces within the spine shoot upward of 1,600 pounds. It’s not hard to imagine that when the spine is repeatedly required to withstand this weight or load through work or exercise that an injury may result. When this load is subjected to a weak back, it can cause serious damage to the vertebral disks of the spine.
If the muscles aren’t able to support or spread the load that is introduced to the body, it will focus to one or two particular areas in the body, resulting in an overload and possible injury. It is important to remember that while the force may seem astronomical, it is based on how torque and lever arms interact with one another. For example, if you hold a tire iron too close to the pivot point when changing a tire, you will not be able to generate enough torque to break the bolt loose. In order to break it loose, you must grab the tire iron as far away from the pivot point as possible to generate more torque. The same applies to the forces on the body. If we hold a weight further away from our body the amount of force exerted to our muscles and joints jumps up exponentially, reducing the length of how long we can maintain that position.
Given the amount and application of force to the structures of our back, it is imperative that we eliminate the habit of flexing the back with load. Instead, we should utilize spine-safe exercises that work to increase the abdominal- and core-muscle capacity. If we continue to load the discs improperly, it can lead to back injuries such as spinal disc herniation or muscle injury.
Some simple exercises that can take the place of sit-ups are planks, modified planks or bird dog, depending on the fitness of the participant. Squats are also a great exercise provided that your squat mechanics are good. Ninety percent of people display poor or subpar squat mechanics, so it is important to learn the correct way before loading or adding weight to a squat.
As long as you follow good body mechanics and movement patterns while not applying unsafe force, you can virtually do any exercise safely.
If you have any questions about starting or continuing exercises that are safe for your back, schedule an appointment today. In the meantime, visit our YouTube channel to learn more about proper and safe exercises.