The Mobility & Stability Concept by Daniel Mansueto
Humans are designed to be able to perform complex movements. Moreover, with evolution, our physiology has progressively evolved; walking with two limbs instead of walking on all fours (quadruped movement), spine size decreases, improved intelligence and cognitive function etc.
Our body is constructed of a skeleton with interconnecting joints that allow movement in various planes. Here are the different types of joints found in the human skeleton, these are otherwise known as synovial joints:
- Saddle Joint (Thumb)
- Hinge Joint (Elbow and knee)
- Ball and Socket Joint (Shoulder and Hip)
- Pivot Joint (Found in the neck between C1 and C2 vertebra)
- Condyloid Joint (Wrist between the radius and carpal bones)
The mobility-stability concept has been growing in the fitness industry, and throughout the years’ multiple professionals have researched the importance of mobility and stability. Stuart McGill, Mike Boyle, Gray Cook, Bill Hartman, and Eric Cobb all come to mind; all professionals focusing on rehabilitation, strength and conditioning for athletic performance.
Nowadays, there are some misconceptions regarding mobility training as there isn’t much awareness of the subject. Hence, I will try to help you understand how truly inter-related mobility and stability are together with other contributing factors that could be affecting one’s performance.
The Interconnecting effects of Mobility and Stability; the two sides of the same coin.
Like the famously know concept of the Yin and Yang, Mobility and Stability are complementary in nature. If one strives to improve mobility at a joint, stability will be sacrificed to a certain degree. This works oppositely as well; the more you strive to stabilize a joint, the more you inherently restrict its mobility.
Before we venture off deeper into the subject, let’s distinguish the difference between the two terms according to Bill Hartman (Hartman, 2017):
- Mobility is the ability to produce a desired movement.
- Stability is the ability to resist an undesired movement.
The concept of mobility revolves around specific key factors: joint architecture, soft-tissue length, and neural control over the surrounding muscles. Now with regards to stability, the action itself is created via a blend of active and passive influences. The passive factors are the entire joint structure (ligaments, capsule, architecture), together with the active factors such as motor neural control, muscle structure, strength etc. (Robertson, 2007).
Now when we observe every joint in the human skeleton, we can identify that each joint serves a specific purpose – to produce a given movement. The author and strength coach Mike Boyle took the concept to a whole new level when he introduced the “joint-by-joint” approach to training which involves specific training to each joint specified to the movement pattern and required stability/mobility (Boyle, 2007). Through his research, the author gave us a base of understanding of the movement requirements of each joint. Below are the joints and their primary need (Boyle, 2007):
- Foot: Stability
- Ankle: Mobility
- Knee: Stability
- Hip: Mobility
- Lumbar Spine: Stability
- Thoracic Spine: Mobility
- Scapula: Stability
- Gleno-Humeral Joint: Mobility
- Elbow: Stability
The chart in itself acts as a guide or baseline of where the joint movement state should be. However, it can not be applied injudiciously without proper assessments. Yes, the hip generally needs to be more mobile, but certain individuals have excessive hip mobility; thus, they require more stability. This also applies for other joints; too stable joints due to lifestyle factors require mobility training etc. Take the knee for example, according to the “joint-by-joint” approach the knee needs more stability. But in fact, according to the research done by (Ward, et al., 2018) involving “Quadriceps Neuromuscular Function and Jump-Landing Sagittal-Plane Knee Biomechanics After Anterior Cruciate Ligament Reconstruction”, the authors suggested that a knee with restricted sagittal plane mobility would be at an increased risk of injury.
So instead of looking at the joint-by-joint approach in black and white, we have to look at things in a greyscale fashion; joints in the “mobility” section have freedom of movement in all planes but can require stability training, and the same concept but in the opposite for the joints that fall under the “stability” section.
If you refer to figure 2, we have a representation of joints that traditionally need more stability, on the left, whereas on the right we have joints that require more mobility. By understanding the architecture of the joint the concept becomes clearer. Let’s take the hip and shoulder as an example. Both have a similar structure, but if you look closer at the structure, the femoral head is placed at a higher and tighter position compared to the humeral head (Veeger & van der Helm, 2007). Also, the hip socked is deeper and larger compared to the glenoid. Thus, the hip has a similar yet different range of mobility. Even though the shoulder & hip are similar in architecture, the hip will naturally have more stability than the shoulder.
Okay, let’s take an even more complex joint: the scapula-thoracic joint. Some argue that the joint needs more stability while others say it needs more mobility. Let’s break it down to obtain a better understanding. Research has shown that if an individual is diagnosed with glenohumeral instability, their scapulae is likely to be unstable, hence leading ta a higher risk of injury (Kibler, 1998). Now, on the other hand, it is a common fact that during exercise or any sort of athletic performance, the performer will require a degree of stability in the scapulae (protraction, retraction, and depression). However, having too much stability is also a big issue according to (Sahrmann, 2002). Not having adequate mobility in the scapulae will most likely increase the chance of impingement injuries.
As clearly shown above mobility and stability work in unison. There has to be a degree of balance between each other. It all falls on the understanding of the joint architecture, soft tissue surrounding them, and their movement pattern.
The Difference between Mobility training and Loaded Mobility.
According to (McGill, 2007) strength training should be structured specifically to the needs and requirements of every patient. This means creating stiffness in certain joints and improving mobility in others together with maintenance. There is no definite statement that suggests the exact amount of movement at each joint, it’s impossible (McGill, 2007) states. Strength training should be beneficial for the body. One should be able to perform a movement with the full range of motion and pain-free. Otherwise, if there are any issues they should be understood and addressed.
When strength training is executed correctly with proper practice and programming, the individual’s posture and mobility improve (Veeger & van der Helm, 2007).
Another example would be the gleno-humeral joint. The mobility needs of this joint are vastly different between a high-level discus thrower and your average strength trainee. As well, understand that it’s not necessarily about more total mobility as it is about optimizing mobility for your given sport (Veeger & van der Helm, 2007).
So, what if strength training is introduced to specifically strengthen joints during movements that would normally put the individual at risk of injury such as ankle sprains and any other soft tissue related injuries? That’s where stiffness training comes in, the last contributing factor to the mobility and stability continuum.
Understanding Stiffness and using it to improve performance.
(Sahrmann, 2002) describes stiffness as passive resistance to stretching. Stiffness works hand in hand with mobility and stability. When having a balance between the three factors, the individual will be able to perform any desired movement optimally or cause faults in the movement pattern. (Boyle, 2007) in his book related the concept of stiffness to two bands pulling on each other. One band is big and strong (for example the hip stiffness), and the other band is smaller and weaker (represents the lower back stiffness). Since both bands aren’t equal, the bigger band is going to overpower the smaller band and deform. Take the butt-wink in a squat. During the deep flexion phase, the stiffness in the hip overpowers the stiffness in the lumbar spine, thus, the lower back rounds. Therefore, the lumbar spine (smaller band) must be strengthened to achieve a higher degree of stiffness to counter that of the hips.
Proper assessment is always required beforehand. The individual might also need to achieve more mobility in the hips, which will complement the lumbar spine stiffness. This also applies to other contributing movers in the squat such as the ankle and knee. Regardless, the same concept should be applied accordingly.
When you hear the term “stiffness” the following things come to mind: immobility, inflexible, tightness, ridged etc. All negative factors, however, stiffness is not all that bad. If you observe elite-level athletes or well-educated exercise performers , they know how to utilise stiffness to produce more powerful movements and reduce the risk of injury (balance of mobility, stability and stiffness) (Kibler, 1998). With proper programming, one can in theory achieve stiffness and strength in for a example: ankle pronation and supination or any other excessive movement that put the individual at risk of injury. Focusing on the “band” concept described by (Boyle, 2007), stiffness can be achieved in mobile joints to reduce the risk of injury and prolong joint health, and improve overall performance whether is sport-specific or not.
The concept of stiffness is vast and indeed very interesting but requires more research. But in the end, it is essential to be aware of its presence and how it is influencing your exercise performance.
Summarized version:
The mobility-stability concept has been growing in the fitness industry, and throughout the years’ multiple professionals have researched the importance of mobility and stability. Stuart McGill, Mike Boyle, Gray Cook, Bill Hartman, and Eric Cobb all come to mind; all professionals focusing on rehabilitation, strength and conditioning for athletic performance.
Nowadays, there are some misconceptions regarding mobility training as there isn’t much awareness of the subject. You see. Mobility and Stability work hand-in-hand, together with another contributing factor which is stiffness (Hartman, 2017). Depending on the desired movement to be performed there has to be an equal amount of the three factors present to allow the performer to perform the movement with full range of motion, pain-free and optimal control (Boyle, 2007). Take a barbell squat, for example, the performer must have adequate mobility in the hip, ankle, knee, and thoracic spine, but at the same time, there has to be a degree of stability to limit excessive movement (Ward, et al., 2018) (McGill, 2007) (Sahrmann, 2002). As for stiffness, the performed must be educated and well trained on how to activate specific parts of his body to eliminate any excessive movement and protect the spine. This is achieved by proper screening, programming and continuous practice. Research has shown that there is a specific state in which joint should be (Boyle, 2007), where the joint should be stable or mobile. But that’s in black and white. We have to look at in a greyscale fashion. Depending on the physical state of the individual each joint must be trained accordingly whether if it’s an athlete or a normal individual (Boyle, 2007). Now the same concept can also be applied to create strength and stiffness during excessive movement such as ankle pronation, where normally there is the high risk of an ankle sprain, but with adequate progression and loading, we can say that ultimately we can “bulletproof” the ankles and eliminate the risk of ankle sprains! Moreover, there is still a lot of research to be done on this subject as it is continuously evolving in the fitness industry. When in doubt seek help from an experienced professional to help you achieve better mobility and stability, thus, improving your overall athletic performance!
References
- Boyle, M., 2007. A Joint-by-Joint Approach to Training.
- Hartman, B., 2017. From my notebook: On Stability. [Online]
Available at: https://billhartmanpt.com/from-my-notebook-on-stability/
[Accessed 23 January 2021]. - Kibler, W., 1998. The Role of the Scapula in Athletic Shoulder Function.. Am J Sports Med, Volume 26, pp. 325-337.
- McGill, S., 2007. Designing Exercise for the Painful Low Back. Chicago, Perform Better Functional Training Summit.
- Robertson, M., 2007. The Mobility-Stability Continuum: A New Look at Joint Health. [Online]
Available at: https://www.t-nation.com/training/mobility-stability-continuum?fbclid=IwAR2dmlQmfMbpf_RcVRaoTA8ZYOHshl81YCqE7uLSDi-A9jM77OwluJh8wsA
[Accessed 23 January 2021]. - Sahrmann, S., 2002. Diagnosis and Treatment of Movement Impairment Syndromes. Louis: Mosby, Inc.
- Veeger, H. & van der Helm, F., 2007. Shoulder function: The perfect compromise between mobility and stability. Journal of Biomechanics, 40(10), pp. 2119-2129.
- Ward, S. H. et al., 2018. Quadriceps Neuromuscular Function and Jump-Landing Sagittal-Plane Knee Biomechanics After Anterior Cruciate Ligament Reconstruction. Athl Train, 53(2), pp. 135-143.
