by NSCA's Guide to Program Design
Kinetic Select May 2017
The following is an exclusive excerpt from the book NSCA's Guide to Program Design, published by Human Kinetics. All text and images provided by Human Kinetics.
The major concern with balance and joint-stabilization exercises is to avoid potentially dangerous movements that depend on the preparedness of the athlete or patient and on the state of the healing tissue. Slow progression should be followed toward extreme ranges of motion or movements where joint stability is compromised or susceptibility to injury is increased. For the majority of joints, extreme ranges of motion are usually susceptible to injury, since both muscle force and neuromuscular control are diminished. For example, combined abduction and outer shoulder rotation or increased ankle inversion are positions in which the shoulder and ankle joints are relatively unstable and are susceptible to injury. These ranges of motion should be avoided in early stages of rehabilitation. Another example is patellofemoral pain syndrome, where movements in 30° to 60° range of knee flexion should be avoided to avoid overstressing the articulation surface of the patella. Here, compressive force is at its highest, which stresses the patellar cartilage. Perturbing forces in extreme positions should be introduced gradually. Athletes who are healthy but untrained should follow the same principle, slowly moving to more vulnerable and unstable ranges of movement.
The speed of movement should be increased slowly to enable good control over joint stability. Higher velocities of movement in early stages, when the subject is still unaccustomed to the movement pattern, can cause diminished control of movement. For example, performing torso stabilization while sitting in an almost static, erect position on an exercise ball can be dangerous if the additional movements presented by the strength and conditioning professional are too fast. This results in ineffective reflexive stabilization of abdominal muscles and possibly unsafe amplitudes of movement.
In programs for sport-injury prevention, rate of movement should slowly progress toward the speeds used in the sport, enabling joint stabilization during fast, sport-specific actions. For example, stabilization exercises of the shoulder joint for throwing athletes should progressively move toward more explosive movements, enabling adaptation of the neuromuscular system to appropriately stabilize the joint during pitching, throwing the ball in cocked position, and ending a throw. In addition to a progressive increase in the speed of movement, athletes should work on eccentric and explosive strength, preparing the soft tissue of the joint and the musculoligamentous area to cope with increased stress.
Bigger forces can be introduced with training, but not until the subject has mastered balance or functional-joint-stabilization tasks. Acquiring an appropriate movement strategy is more efficient if the load applied is not too high. This holds especially true in case of rehabilitation programs.
For uninjured athletes, training for balance and functional joint stabilization should always be challenging. Active involvement of both the athletes and their neuromuscular systems enables conditioning. If an exercise does not demand corrective movements, training will be ineffective, since the neuromuscular system is not required to react and adapt to perturbation or reestablish joint stability and body equilibrium.
Progression from less to more demanding tasks is suggested. For example, a progression from monoaxial to multiaxial balance board is recommended. Athletes should also progress from a bigger to a smaller support surface and incorporate longer work intervals, additional tasks, and a higher frequency of oscillation into their routines. When athletes master a movement, the strength and conditioning professional should upgrade it or introduce a new, unfamiliar movement. Since adaptations of the neuromuscular system are induced by increasing the demand of conducting a task, this rule should be followed.
Developed by the National Strength and Conditioning Association (NSCA), this text offers strength and conditioning professionals a scientific basis for developing training programs for specific athletes at specific times of year. The book is available in bookstores everywhere, as well as online at the NSCA Store.