الفهرس 
Normal gait & abnormal gait patternOnly 14 pages are availabe for public view
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Abstract
Generating an efficient and stable gait pattern relies on a complex interaction between multiple systems in the body: the neurological system plans a motion, the muscles generate forces, and the skeleton provides a framework upon which the muscles act to create motion. Problems at each of these levels are common in children with cerebral palsy. [1]
Many children with cerebral palsy walk in a crouch gait, a movement pattern characterized by excessive flexion of the knee in terminal swing and throughout the stance phase of the gait cycle. If left untreated, this pathological gait pattern increases the cost of locomotion and tends to worsen over time leading to joint pain and degeneration. [2]
Researchers and clinicians have proposed several hypotheses about why these children walk with excessive stance phase knee flexion. First, spasticity or contracture of the hamstrings muscles is thought to restrict knee extension, thus hamstrings lengthening surgery is commonly prescribed to alleviate the excess forces generated by these muscles. Second, bone deformities in particular excess torsion of the tibia are believed to contribute to crouch gait by reducing the capacity of muscles to generate extension accelerations at the hip and knee joints. As a consequence, tibial derotation osteotomies are often performed for children with crouch gait to restore normal bone alignment. Muscle weakness has also been identified as a possible contributor to crouch gait, and can be targeted with strength training. [3]
Before the development of computer-based gait analysis systems, careful clinical observation was the primary method of diagnosing gait disturbances in children with cerebral palsy. It is still an essential component in making the diagnosis. Modern quantitative gait analysis uses high-speed motion picture cameras from different angles, retro reflective markers on the surface of the skin aligned with palpable skeletal landmarks, and force platforms to measure the various components of gait Kinematic data are provided that are presented in a waveform that represents the three-dimensional motion of the joints during the gait cycle. [2]
While many patients respond positively to treatment for their excessive knee flexion, the outcome of surgery and other therapies designed to address crouch gait are variable and unpredictable.
Since there are many possible causes of crouch gait, appropriate treatments must be chosen on a patient-specific basis and currently there is
no standardized protocol or set of guidelines for planning which surgeries an
individual subject should receive