Part II: The Core – Mobility and Stability

Working at a gym allows me to watch people exercise. It never ceases to amaze me how wrong people exercise. One of the biggest concepts I stress to all my clients is stability and mobility and then strength. You have no idea how many times I have seen people add load to squats when they can’t even do a bodyweight squat correctly.

Part of core training should include mobility and stability exercises. Musculoskeletal pain is very common in the American population today. Most of it is due to lack of physical activity and lifestyle choices. Lower back pain is one of the major forms of musculoskeletal degeneration in the adult population, affecting nearly 80% of all adults. Research has shown that lower-back pain is predominant among those who work desk jobs and sit longer than 3 hours at a time. A majority of the age-group athletes competing in endurance sports work full-time jobs, often desk-based. Back and other joint injuries can cause muscle imbalances that will affect sports performance.

In the last post we discussed the kinetic chain and core anatomy. Impairment or injury to the human movement system rarely involves one structure. Impairment in one system leads to compensations and adaptions in other systems. For example, I have right hip issues that often results in my right foot developing plantar fasciitis. This happened to me this past fall and I was forced to take several months off from running to heal the injury before I embarked on Ironman training. It was not fun to say the least.

Now, what does this all have to do with mobility, stability, and core training? Everything. If you don’t have full range of motion and/or the stability required of your joints then you’re bound to end of getting injured at some point. Most athletes have muscle imbalances and faulty movement patterns cause by their respective sports. For example, many cyclists suffer from piriformis syndrome, where the piriformis (a muscle that externally rotates the leg) becomes weak because the gluteus maximus is being overworked and can lead to pain or numbness down the leg or in the hip. Runners often have IT band and knee problems.

According to Bill Hartman, mobility is the ability to produce a desired movement; whereas, stability is the ability to resist an undesired movement. When examining mobility of joints, one must observe the architecture of the joint, soft-tissue length, and neutral control of the surrounding muscles. Stability on the other hand is a blend of passive and active influences. Passive influences of joint stability include the anatomy of the joint – the capsule, ligaments, and the architecture of the joint. The active influences include motor control of the surrounding musculature and muscular strength.

Mike Boyle, one of my favorite trainers, has divided mobility and stability up in a “joint-by-joint” approach to training.


Foot Stability
Ankle Mobility
Knee Stability
Hip Mobility
Lumbar Spine Stability
Thoracic Spine Mobility
Scapula Stability
Gleno-Humeral Joint (Shoulder) Mobility
Elbow Stability

Now, this approach is not completely black and white. There is definitely some gray area, especially since everyone is different. Another way to look at mobility and stability is through the mobility-stability continuum. All joints need some degree of mobility and some degree of stability.

Stable       Mobile
Knee Elbow Scapula Hip Shoulder

Mike Robertson, another one of my favorite trainers, said that someone once told him that “strength training cements your posture and mobility” and whether that posture is good or bad is up to you. If you don’t have full range of motion of your hip joints then why are you going to add weight to your back squat? It’s better to work on hip mobility and activating weak hip muscles to get full range of motion and then add weight. Just because you want to look like a badass at the gym and back squat 150 lbs doesn’t mean you should because you’ll probably end up looking like a dumbass when you injury your back because you have tight hip flexors and your lower back arches.

Stay tuned for some posts on how to conduct a functional movement screen, corrective exercises to aid in good posture, and exercises to help with mobility and stability!


  1. Clark MA, Lucett SC. NASM Essentials of Corrective Exercise Training. New York, NY: Wolters Kluwer; 2011.
  2. Robertson M. Mobility-Stability Continuum. Available at: Accessed February 9, 2013.
Follow on Bloglovin

One thought on “Part II: The Core – Mobility and Stability

  1. Pingback: Part III: The Core – A Case for a Functional Movement Screen | The Rhyme and Reason

Leave a Reply