The most common system of resistance training used with dynamic exercise against constant or variable resistance is progressive resistance exercise (PRE). A later section of the chapter, which covers systems of training using mechanical resistance, addresses PRE.
Dynamic constant external resistance (DCER) exercise is a form of resistance training where a limb moves through a ROM […]

A dynamic muscle contraction causes joint movement and excursion of a body segment as the muscle contracts and shortens (concentric contraction) or lengthens under tension (eccentric contraction). The term concentric exercise refers to a form of dynamic muscle loading where tension in a muscle develops and physical shortening of the muscle occurs as an external […]

Isometric exercise is a static form of exercise in which a muscle contracts and produces force without an appreciable change in the length of the muscle and without visible joint motion. Although there is no mechanical work done (force × distance), a measurable amount of tension and force output are produced by the muscle. Sources […]

From a broad perspective a load can be applied to a contracting muscle in two ways: manually or mechanically.
Manual Resistance Exercise
Manual resistance exercise is a type of active-resistive exercise in which resistance is provided by a therapist or other health professional. A patient can be taught how to apply self-resistance to selected muscle groups. Although […]

The types of exercise selected for a resistance training program are contingent on many factors, including the cause and extent of primary and secondary impairments. Deficits in muscle performance, the stage of tissue healing, the condition of joints and their tolerance to compression and movement, the general abilities (physical and cognitive) of the patient, the […]

Balance of Stability and Active Mobility
Control of the body during functional movement and the ability to perform functional tasks require a balance of active movement superimposed over a stable background of neuromuscular control. Sufficient performance of agonist and antagonist muscles about a joint contributes to the dynamic stability of individual joints. For example, a person […]

Periodization, also known as periodized training, is an approach to resistance training that builds systematic variation in exercise intensity and repetitions, sets, or frequency at regular intervals over a specified period of time. This approach to training was developed for highly trained athletes preparing for competitive weight-lifting or power-lifting events. The concept was designed to […]

The velocity at which a muscle contracts significantly affects the tension that the muscle produces and subsequently affects muscular strength and power. The velocity of exercise is frequently manipulated in a resistance training program to prepare the patient for a variety of functional activities that occur across a range of slow to fast velocities.
Force-Velocity Relationship
The […]

The mode of exercise in a resistance exercise program refers to the form of exercise, the type of muscle contraction that occurs, and the manner in which the exercise is carried out. For example, a patient may perform an exercise dynamically or statically or in a weight-bearing or non-weight-bearing position. Mode of exercise also encompasses […]

Isokinetic exercise is a form of dynamic exercise in which the velocity of muscle shortening or lengthening and the angular limb velocity is predetermined and held constant by a rate-limiting device known as an isokinetic dynamometer. The term isokinetic refers to movement that occurs at an equal (constant) velocity. Unlike DCER exercise where a specific […]

Rest is a critical element of a resistance training program and is necessary to allow time for the body to recuperate from the acute effects of exercise associated with muscle fatigue or to offset adverse responses, such as exercise induced, delayed-onset muscle soreness. Only with an appropriate balance of progressive loading and adequate rest intervals […]

Frequency
Frequency in a resistance exercise program refers to the number of exercise sessions per day or per week. As with other aspects of dosage, frequency is dependent on other determinants, such as intensity and volume as well as the patient’s goals, general health status, previous participation in a resistance exercise program, and response to training. […]

In resistance training the volume of exercise is the summation of the total number of repetitions and sets of a particular exercise during a single exercise session multiplied by the resistance used. The same combination of repetitions and sets is not and should not be used for all muscle groups.
There is an inverse relationship between […]

The intensity of exercise in a resistance training program is the amount of resistance (weight) imposed on the contracting muscle during each repetition of an exercise. The amount of resistance is also referred to as the exercise load (training load), that is, the extent to which the muscle is loaded or how much weight is […]

Stabilization refers to holding down a body segment or holding the body steady. To maintain appropriate alignment, ensure the correct muscle action and movement pattern, and avoid unwanted substitute motions during resistance exercise, effective stabilization is imperative. Exercising on a stable surface, such as a firm treatment table, helps hold the body steady. Body weight […]

Just as correct alignment and effective stabilization are basic elements of manual muscle testing and dynamometry, they are also crucial in resistance exercise. To strengthen a specific muscle or muscle group effectively and avoid substitute motions, appropriate positioning of the body and alignment of a limb or body segment are essential. Substitute motions are compensatory […]

Many elements (variables) determine whether a resistance exercise program is appropriate, effective, and safe. This holds true when resistance training is a part of a rehabilitation program for individuals with known or potential impairments in muscle performance or when it is incorporated into a general conditioning program to improve the level of fitness of healthy […]

The use of resistance exercise in rehabilitation and conditioning programs has a substantial impact on all systems of the body. Resistance training is equally important for patients with impaired muscle performance and individuals who wish to improve or maintain their level of fitness, enhance performance, or reduce the risk of injury. When body systems are […]

Knowledge of the factors that influence the force-producing capacity of normal muscle during an active contraction is fundamental to understanding how the neuromuscular system adapts as the result of resistance training. This knowledge, in turn, provides a basis on which a therapist is able to make sound clinical decisions when designing a resistance exercise program […]

The SAID principle (specific adaptation to imposed demands) suggests that a framework of specificity is a necessary foundation on which exercise programs should be built. This principle applies to all body systems and is an extension of Wolff’s law (body systems adapt over time to the stresses placed on them). The SAID principle helps therapists […]

A guiding principle of exercise prescription that has been one of the foundations on which the use of resistance exercise to improve muscle performance is based is the overload principle. Simply stated, if muscle performance is to improve, a load that exceeds the metabolic capacity of the muscle must be applied; that is, the muscle […]

The three elements of muscle performance strength, power, and endurance can be enhanced by some form of resistance exercise. To what extent each of these elements is altered by exercise depends on how the principles of resistance training are applied and how factors such as the intensity, frequency, and duration of exercise are manipulated. Because […]

Muscle performance refers to the capacity of a muscle to do work. Despite the simplicity of the definition, muscle performance is a complex component of functional movement and is influenced by all of the body systems. Factors that affect muscle performance include the morphological qualities of muscle; neurological, biochemical, and biomechanical influences; and metabolic, cardiovascular, […]

An understanding of the disablement process as well as knowledge of the process of making informed clinical decisions based on evidence from the scientific literature are necessary foundations of comprehensive management of patients seeking and receiving physical therapy services. Provision of quality patient care involves the ability to make sound clinical judgments, solve problems that […]

As shown in , modifying risk factors through an intervention such as therapeutic exercise is an important tool for reducing or preventing the major components of the disablement process. Risk factors related to disablement are influences or characteristics that predispose a person to the process of disablement. As such, they exist prior to the onset […]

Understanding the relationships among pathology, impairments, functional limitations, and perceived disability is fundamental to the prevention or reduction of disability. The presence of functional limitations may or may not lead to loss of independence and result in disability. Take, for example, a relatively inactive person with long-standing osteoarthritis of the knees. The inability to get […]

The final category of the disablement continuum is disability. There is a growing body of knowledge suggesting that physical impairments and functional limitations directly contribute to disability.Consequently, an approach to patient management that focuses on restoring or improving function may prevent or reduce disability and may have a positive impact on quality of life.
A disability […]

Functional limitations in the physical domain deal with the performance of sensorimotor tasks, that is, total body actions that are typically components or elements of functional activities. These activities include basic activities of daily living (ADL), such as bathing, dressing, or feeding, and the more complex tasks known as instrumental activities of daily living (IADL), […]

Functional limitations, the third component of the disablement model, occur at the level of the whole person. They are the result of impairments and are characterized by the reduced ability of a person to perform actions or components of motor skills in an efficient or typically expected manner. For example, restricted range of motion (impairment) […]

Impairments are the consequences of pathological conditions; that is, they are the signs and symptoms that reflect abnormalities at the body system, organ, or tissue level. Impairments can be categorized as arising from anatomical, physiological, or psychological alterations as well as losses or abnormalities of structure or function of a body […]