THE USE OF ISOKINETICS IN DIAGNOSIS AND TREATMENT OF MUSCLE
DYSFUNCTION
Egić Božidar,Veber Dalibor
The complexity of a locomotor system and the power of adaptation it, in fact the
nervous system, can exert is best demonstrated through variety of sports, dances
and rituals humans engage to. Physiological adaptation is sometimes so large
that it is hard to discern when or where begins the pathology. The theory of
developmental kinesiology provides us with great help by defining the ideal
physiological motor patterns like role models we should strive for. With the
physiological development of a child in utero and during the first few years of
life, there is a gradual development of posture as a result of central nervous
system maturation and release of the genetically encoded motor programs. This
is a spontaneous process, taking place under the influence of gravity and proper
environmental stimuli. Muscle synergies are formed, while contractions of the
antagonists become balanced, resulting in equilibrium between the function of
the phylogenetically older, tonic, and phylogenetically younger, phasic, part of
the musculoskeletal system. The influence of this balance irradiates to the joints
and enables the movement in the neutral zone (Panjabi) or, put in another
words, enables the joint centration during the movement (Kolář). Moreover,
there is minimal energy expenditure and articular surfaces are in maximal
contact, thereby protected from overloading. Simply put, movements have
reached biomechanical perfection.
If this harmony becomes impaired, usually in the sense of facilitation of the tonic
or inhibition of the phasic system, a pattern of imbalance develops that spreads
throughout the system like a reflex, shedding some light on the mutual
connection of distant muscles along the way. Given that motor patterns are
genetically defined and hence predictable, as taught by developmental
kinesiology, the same predictability can be applied to impaired muscle reactions.
By virtue of this observation, Janda has categorized dysfunctions of the muscular
system in three major syndromes: upper crossed syndrome, lower crossed
syndrome, stratification syndrome. Functional pathology or dysfunction of the
locomotor system is the most frequent cause of pain. It often affects all parts of
the locomotor system simultaneously, from passive (bones, joints, ligaments),
active (muscles, fascia) to control part (peripheral and central nervous system,
motor patterns), creating chain reactions and complex clinical syndromes hardly
explainable in terms of cause and effect. There are multiple causes of
dysfunction, but the end result is always the same, pain as a first warning sign
and impairment of static and/or dynamic function of the locomotor system.
Structural changes are mostly absent or of marginal significance. Spine is
probably the best example of presented pathophysiological process, because the
pain of spinal origin is mostly analyzed only locally, where we seek for
responsible structural pathology. However, if we confuse the source of pain for
the cause of pain, we are more than often destined to failure. Moreover, the
causative factor affects only the local level in the beginning, leading to reflex
changes and adaptation. If this is insufficient, its influence gradually radiates to
the higher levels of the central nervous system and impairs the central motor
patterns, leading to global pathology. In this way, local dysfunction becomes
global and spine can be the cause of the problem, but also just one link in a chain
of global dysfunction of the locomotor system.
Dysfunction of the locomotor system is a complex term. It is defined as
imbalance (facilitation or inhibition) between motor units of single or group of
muscles and becomes visible through inadequate motor stereotypes that lead to
inadequate positioning of articular surfaces during the movement. Described
pathological adaptation is associated with reflex changes which can lead to many
symptoms, from pain to visceral problems. In treatment it is important to find
the root of the problem that usually hides far away from the source of pain.
Along numerous diagnostic and kinesitherapeutic procedures, isokinetic
diagnosis and training can be very helpful as the root of the problem frequently
lays in the muscle imbalance. By measuring the parameters of isokinetic muscle
contraction, using the isokinetic dynamometer, one can determine the muscle
strength, work and endurance. These results are later analyzed and used for
planning and performing isokinetic training. The advantages of isokinetic
training are efficiency, safety, reproducibility and comparability. The drawbacks
are nonphysiological contraction (constant angular speed), impossibility to
achieve neural reactions, motor learning and complexity of the movement (3D).
The scope of the use of isokinetics is wide, from prevention, rehabilitation after
trauma or surgery, various pain syndromes of muscular origin, to sports training.
Contraindications are few, the use is simple as is the storing of data, an
important consideration regarding the limited amount of time available for a
patient. In spite of all the benefits of isokinetics, it has to be viewed as just one
part of the rehabilitation process. The complexity of the locomotor system and
the chain reactions which result from its dysfunction require multidisciplinary
approach in the treatment.
KEY WORDS: isokinetics, dysfunction, locomotor system, chain reaction, pain
syndrome, rehabilitation, developmental kinesiology