Our clients cooperate with what we ask of them. Keeping regularly scheduled appointments, showing up on time for their appointments and giving 24-hour notice if they must cancel all make us happy. But what about when your client does not cooperate by moving the way you want them to during certain exercises? You might give them multiple demonstrations, auditory cues and guide them kinesthetically, and they still won't cooperate. You might even threaten to take away their lunch money, and the result is the same.
At this point, we must concede that the client may want to cooperate but cannot. What you are asking them to do is not part of their current motor control repertoire. But with the right application of corrective exercises, you can expand your client's motor control repertoire and have them performing at their best.
Corrective exercises are movements or postures that are used to produce desirable changes in joint positioning, stability and movement strategies, thereby minimizing or eliminating compensations and producing efficient movement patterns. Corrective exercises should precede more integrated exercises because they can cue the client's motor system to respond in a more desirable way and assist in removing or improving biomechanical constraints.
The Movement Triad
All movements of the body including exercises have three primary components to them, which I refer to as the Movement Triad:
1. Physiological — energy systems used, recovery between sets, exercise dosage (sets, reps, load, frequency, intensity, duration) and cardiovascular responses
2. Biomechanical — direction(s) of force application, length of the lever(s) used, positional relationship to the gravity vector, range of motion, joint degrees of freedom and muscle fiber orientation
3. Neurological — processing of proprioceptive information from the periphery (skin, joints, muscles/tendons, eyes and inner ear), muscle activation patterns, which includes the timing, amount and rate of muscle activation and the interplay between any required movements with existing motor programs
It is critical to consider the Movement Triad with each and every exercise we provide our client or athlete. A familiar trap for health and fitness professionals to fall into is emphasizing the component of the Movement Triad with which they have the greatest level of training, experience and comfort. Doing so can have adverse effects on the outcome of the exercise and can be potentially dangerous to the client or athlete.
For example, the health and fitness professional with an exercise physiology degree that specializes in clients with weight loss goals may view exercise design in terms of energy expenditure and substrate utilization. In doing so, they pay little attention to the mechanical stresses occurring or the repetition of sub-optimal movement strategies during the exercise session. The likelihood of this client developing musculoskeletal issues becomes greater when the emphasis is on only one component of the Movement Triad.
Corrective exercises must take full advantage of the Movement Triad in the same way to produce the desired changes we seek with our clients. In fact, with corrective exercises, utilizing the components of the Movement Triad may be more important as we ask the client's body to produce unfamiliar, novel movements.
Some of the fundamental objectives with corrective exercise might include improving flexibility within specific muscle groups, improving strength within specific muscles groups and improving stability around specific joints. Using these objectives, we can consider as an example the client who has the common postural deviation of rounded shoulders with thoracic flexion. This client would need to improve flexibility of the chest and anterior shoulder girdle musculature and would also need to improve strength and stability of the thoracic extensors, rhomboids and middle and inferior trapezius.
Let's look at how we can apply the Movement Triad to this example:
Flexibility: Muscles have viscoelastic properties. The joints require the production of synovium to move smoothly with reduced friction. If heat is not generated in the tissue prior to stretching, the viscous properties of the muscle tissue will be resistive to lengthening, and the articulating surfaces of the joints may not move optimally due to higher degrees of friction.
Strength: With corrective exercises, the sets and repetitions should be based on quality of the movement. Corrective exercise movements should not have the client work to failure. Fatigue to the targeted muscle groups promotes an environment for compensation by synergistic muscles and defeats the purpose of the corrective intervention. Muscle groups fatigued with corrective exercise may be unable to contribute during more dynamic activity that follows.
Stability: Muscular contractions for stabilization occur much more frequently at lower percentages of MVC (maximal voluntary contraction) because stabilization requirements are often of lower demand but for greater periods of time. Improving endurance of our stabilizers should initially take precedence over short bursts of maximal contractions.
Flexibility: The position of the lever, such as the upper extremity when used to stretch the anterior chest wall, can produce different effects on the position of the gleno-humeral joint. This will, in turn, affect the position of the thoracic spine. Both are also affected by the degree of elbow flexion and the influence of the biarticulate biceps brachii on the gleno-humeral joint. Effective lengthening of the anterior chest wall will only occur if the gleno-humeral joint can externally rotate without scapular elevation and upward rotation. Therefore, the position of the hand, the position of the elbow joint, the amount of shoulder flexion and the point of force application all will determine if the desired lengthening occurs.
Strength: Scapular adduction (retraction) is coupled with thoracic extension. Attempts to strengthen the rhomboids and middle trapezius with the thoracic spine in flexion will promote synergistic dominance by the levator scapulae and upper trapezius. If you would like to experience this for yourself, sit on your chair with your arms hanging at your sides. From here, slouch by flexing through your entire spine. Now try to bring your scapulae together while in spinal flexion. You'll see that you are unable to retract your scapulae without elevating your shoulder girdle.
Stability: In an upright vertical posture (i.e. standing or sitting), the thorax is largely dependent upon the hips and pelvis for stability. The thoracic stabilizers need a stable platform from the pelvis to provide the necessary stability, and the thoracic spine will not be properly stabilized posturally or during activity if the hips and pelvis are not stable. Pelvic deviations in any of the three planes will create an undesirable compensation in the thoracic spine.
Flexibility: Long-term postural adaptations and/or overuse adaptations create a bias of the motor neuron pool to shorter, tighter muscles. This becomes a self-perpetuating cycle in that the shorter, tighter muscles get shorter and tighter as they demand more neurological stimulation. This decreases neurological stimulation to the antagonist(s) inhibiting that muscle and reducing its contribution to movement in any of its potential roles (prime mover, synergist, antagonist, neutralizer). Eccentric lengthening of muscles to decelerate gravitational forces and/or external weight is the way the body signals a concentric contraction to overcome the same forces. Decreased flexibility means a reduced ability for the muscle to effectively load eccentrically, which limits force production. Imagine winding up to throw a ball but not being able to get your arm behind your torso. Your throw would turn in to a "push," never fully generating the optimal eccentrically loading of the pecs, anterior deltoid or obliques.
Strength: When performing corrective exercises for strengthening, we begin by keeping the effort at approximately 60% of the client's perceived maximum. The reduced effort allows the body to recruit motor neurons from all muscles involved in the movement sequence. The body can then proprioceptively recognize the difference between their familiar movement patterns and the new one we are attempting to establish. In contrast, higher percentages of effort will require that the body use its most effective (as opposed to efficient) movement strategy. The result is that the client reproduces the undesirable movements patterns we are attempting to correct.
Stability: Much of the information the central nervous system (CNS) receives regarding stability for a joint comes from the mechanoreceptors in the joint capsule. Therefore, the quality of the information to the CNS is dependent on the quality of the joint capsule. Joint capsules that have been damaged due to injury or become lax with overuse can negatively affect the quality of the proprioceptive information to the CNS. Force production of a muscle is secondary to the timing of the contraction. For example, if a muscle designed to stabilize the spine against a sheer force contracts at 100% but is 1/10 of a second late contracting, the damage could already be done. This is often the case in joints where the joint capsule has adapted to long-term postural stress, as with thoracic kyphosis.
Understanding the Movement Triad and its relevance will provide you with a way to self-audit your decision-making process when choosing exercises. It will require you to think through the three components of the exercise and how those components apply to the client or athlete you are working with. The margin for error is often much smaller when working with clients with musculoskeletal challenges and applying corrective exercises. Applying the Movement Triad to your exercise design increases the effectiveness of your program and reduces the risk of injury.
Anthony Carey, MA, CSCS, CES, holds a Masters degree in biomechanics and athletic training and is the owner of Function First in San Diego, California. He is the author of The Pain-Free Program: A Proven Method to Relieve Back, Neck, Shoulder and Joint Pain and the DVDs Corrective Exercise for Powerful Change I and II. For more information and seminar listings, visitwww.functionfirst.com.