The spectrum of degrees or levels at which the most essential neuro-muscular-skeletal components are operating. Function in this regard is based upon and defined by the integrity of and limitations in both joint function and muscle function.
Importance in Exercise
Orchestration of any motor recruitment solution is based upon efficient use of the properly functioning components (joints, muscles) and avoidance of poorly functioning or non-functioning components. Restated, the brain typically employs the “avail-able” and avoids the weak, inhibited, inflamed, etc.
Therefore, training to improve function would require identification of specific neuro-muscular-skeletal deficits or dysfunctions and the introduction of a precisely applied stimulus at the appropriate levels and frequency, thereby providing the opportunity for that joint/muscle’s use in the orchestration of motor recruitment solutions.
In this regard the exercise that most effectively addresses one’s needs or deficits on a given day may in fact look nothing like the gross movement or external outcome/goal. I.e. the most appropriate steps to the goal may look nothing like the goal.
The essential function of muscle is the ability to generate a contraction. This fundamental ability should not be confused with any specific amount of tension production or for any specific activity. Optimally a muscle should be able to generate a detectable contraction at any length as dictated by the excursion of its boney attachments.
Contractile ability can be impaired through a process commonly termed “inhibition” which is considered by many to be a protective mechanism often correlating with intolerance of stresses from chemical to physical.
Contractile ability can also be reduced to the point of impairment through the homeostatic process of “deconditioning” i.e. the atrophy of a muscle, as well as its neurological components and their function. Although atrophy is typically considered the result of a general lack of use, the nature of muscle function makes it susceptible to length-specific alterations in contractile ability. For example, if the currently available extreme of hip joint extension (10˚ beyond zero) is avoided for months or years (e.g. it’s not required for squatting, walking, and certainly not while sitting) thereby preventing the extensor musculature from incurring the associated “crossbridging” relationships, the viability of this end of contraction can become reduced and in time unavailable, thereby impairing output and control. The impairment of internal performance at this point in the range can lead to compensation during external performance. I.e. if an external outcome requires this position (and length of contraction) compensation will be required.
Human motion is not due to “flexibility”. It is due to mobility. And the degree and plane/s of mobility are first and foremost determined by joint structure. The passive/non-contractile architectural components of a joint (normal or pathological) will determine its maximum opportunity for motion. Motion is further regulated or micro-managed by the associated contractile components (i.e. surrounding musculature).
Chondramalacia is the softening of articular cartilage (hyaline) and in more severe stages progresses to a disruption in contact surface coverage, eventually allowing exposure of the bone itself. This progressive process of arthritis is disruptive to the function of a joint as well as the required sensory input.
Osteophytes (or “bone spurs”) are common causes of alterations in joint function with 70% of people over 50 years of age showing their occurrence on MRI.1
Training on Unstable Surfaces
It has been perceived that training on an unstable or “wobbly” surface is more “neurologically challenging” and therefore is best for every goal from cardio, to strength, to rehab, to any sports performance.
The unavoidable fact is that tension production (i.e. output and the associated load) is sacrificed as platform instability is increased. Understanding and appreciating the individual’s needs and goals is vital when determining which form of challenge should be sacrificed and which should be emphasized.
All too often an exercise is chosen or developed because it resembles an activity we want to improve (sports movements, everyday activities, etc.) What we fail to recognize are all of the things we can’t see within that exercise that actually make it dramatically different from the goal-activity, often to the point of becoming detrimental to performance… or even the body!
Conversely, an exercise that looks nothing like the sport or activity can provide benefit to an integral link, and while appearing totally dissimilar to the activity actually improves components that are vital to the performance.
Balance Training vs. Improving Balance
An unstable surface does not inherently improve balance. It dramatically challenges one’s ability to orchestrate a solution for maintaining his/her center of mass over an altered or diminished base of support. If the individual is incapable of maintain the COM/BOS relationship on flat, stable ground then use of an unstable surface/device is an inappropriate progression of challenge.
Furthermore, if an individual’s ankle and foot musculature are functioning inadequately, there are limited “pieces” with which one can generate the solution of balance on any surface. Applying appropriately modulated challenges to the ankle and foot in all directions of required joint and muscular function (both agonistically and antagonistically) can increase the number of options from which the brain may choose in order to generate a solution, and therein reduce the need or degree of compensation.
“Functional training” is “training movement patterns”
Movement as grossly and superficially observed is deceptive when it comes to exercise and performance. Movement is simply a matter of the relationship between the forces of internal effort vs. the forces of external resistance. Therefore, exercise is not the training of “movement patterns”. Exercise is the training of “force patterns,” or more accurately stated, “variations in force producers and force production in response to changes in both internal availability as well as any changes in the force of resistance throughout the range of motion”. Ultimately, exercise boils down to the physics imposed and efficiency of forces produced.
We are told that “functional training” develops “functional muscle”. Functional training as popularized is really just improving the skill of “object (mass/physics) manipulation” i.e. the skill of using the capable portions of the body that are mechanically helpful at any given point in concert with the physics of the object to either a) conserve energy, or b) to produce an external outcome greater than our strength alone can generate throughout the range.
“Functional Training” improves function
If functional training is “doing what you do”, then when do you train the rest? The things you don’t regularly do? Life already is functional training: work, sports, etc. It’s either too much or too little, but rarely is it the ideal stimulus for any individual at any given moment, especially if the goal is a comprehensive health/fitness oriented outcome. True functional training should be focused on improving the details of muscle function and joint function.
“Multi-joint, “integrated” exercises will “fix” weak links.“ But as an analogy keep in mind that “you can only tune a guitar one string at a time.”
Other Myths and Misconceptions
- The external outcome/performance accurately reflects internal performance.
- “Functional” is synonymous with transfer.
- Isolated exercise creates “stupid” muscle.
- Isolated exercise is an attempt to challenge a single muscle.
- Isolating a joint motion is not integrated muscular recruitment.
- Isolating the movement challenge to a single joint disrupts future multiple joint movements and skills.
- A stable base and/or guided path does not improve function.
Ultimately, ignorance of the definition of “function” and industry-wide acceptance of the use of “functional” as nothing more than a marketing term for an exercise trend has caused the unjust condemnation of some exercises and the undeserved glorification of others.
- Internal Performance
- Stable-based challenge
- Restraint: Support and Guidance
- Orchestration & Motor Recruitment
1 Guermazi, A, etal. Prevalence of Abnormalities in Knees Detected by MRI in Adults Without Knee Osteoarthritis: Population Based Observational Study (Framingham Osteoarthritis Study) BMJ 2012;345:e5339 doi: 10.1136/bmj.e5339 (Published 29 August 2012)