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CHAPTER OBJECTIVES
At the completion of this chapter, the reader will be able to:
Understand the importance of manual muscle testing
Perform a gross muscle screening of a patient’s strength
Perform specific manual muscle tests to the shoulder
Perform specific manual muscle tests to the elbow
Perform specific manual muscle tests to the wrist and forearm
Perform specific manual muscle tests to the hand
Perform specific manual muscle tests to the hip
Perform specific manual muscle tests to the knee
Perform specific manual muscle tests to the leg and foot
Perform specific manual muscle tests of the trunk
Describe the strengths and weaknesses of the various grading systems used with manual muscle testing
Interpret the different results that can be obtained from a manual muscle test
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Movement of the body or any of its parts involves considerable activity from the nervous and musculoskeletal systems. The nervous system provides cognition, perception, and sensory integration and is primarily involved in controlling movement, while the nervous and musculoskeletal systems provide the power behind the movement. If a functional limitation is highlighted during the patient’s physical examination, the physical therapist determines the cause of the functional and/or participation restrictions. If the cause is poor muscle performance, a progression of exercises to enhance muscle performance is added to the plan of care (POC). Muscle performance can be assessed by measuring several parameters: strength, endurance, and power. This chapter provides an overview of how the strength component of muscle performance can be assessed. The improvement of muscle strength is an integral component of most rehabilitation programs. Strength may be defined as the amount of force that an individual may exert in a single maximum muscular contraction against a specific resistance or the ability to produce torque at a joint.1 Manual muscle testing, performed grossly or specifically, is a simple way to assess the ability of a muscle, or a group of muscles, to perform a single maximum muscular contraction in an isometric fashion.
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CLINICAL PEARL
The three main types of muscle contraction are2:
Isometric. Isometric exercises provide a static contraction with a variable and accommodating resistance without producing any appreciable muscle-length change.
Concentric. A concentric contraction produces a shortening of the muscle such that the origin and insertion of the muscle move closer together. A muscle performs a concentric contraction when it lifts a load/weight that is less than the maximum tetanic tension it can generate.
Eccentric. An eccentric contraction occurs when a muscle slowly lengthens as it gives in to an external force greater than the contractile force it is exerting. In reality, the muscle does not lengthen but merely returns from its shortened position to its normal resting length.
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