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  • Autism: Autism is a developmental disability that generally begins at birth or within the first three years of life. It is the result of a neurological disorder that changes the way the brain functions and causes problems with social skills and communication throughout life. Autism can be mild or severe and is different for every person. Autism is also known as autism spectrum disorders …Learn More >>
  • Cerebral Palsy: Cerebral palsy is a term used to describe a collection of disorders caused by abnormal brain development or damage to the brain that occurs around the time of birth or early in life. Cerebral palsy causes problems with muscle tone, movement, balance and/or coordination. Symptoms and effects range from mild to severe. In some infants, problems are evident soon after birth. In others, diagnosis comes in later infancy or toddlerhood …Learn More >>
  • Developmental Delay: Developmental delay refers to a child who is not achieving milestones within the age range of that normal variability. Most often, at least initially, it is difficult or impossible to determine whether the delay is a marker of a long-term issue with development or learning (i.e. known as a disability) or whether the child will ‘catch-up’ and be ‘typical’ in their development and learning…Learn More >>
  • Down Syndrome: Down syndrome is the most common cause of mild to moderate mental retardation and the mental and physical medical problems that often come with it. Down syndrome occurs when an person has a full or partial extra copy of chromosome 21. It was named after John Langdon Down, the first physician to identify the syndrome…Learn More >>
  • Epilepsy: Our brains have constant electrical activity in and between cells. A seizure is an abnormal electrical discharge in brain cells that causes a change in normal activity, behavior or movement. Epilepsy is diagnosed when a person has two or more unprovoked seizures. A person who has only provoked seizures (febrile seizures, seizures after head trauma) will not receive an epilepsy diagnosis…Learn More >>
  • Hearing Loss: Hearing loss and hearing impairment are terms used to describe a wide range of hearing losses that occur due to a problem with one or more parts of the ear or the area and neural connections in the brain which process sounds. On one end of the hearing loss spectrum are children who cannot hear sound at all. On the other end of this spectrum are children with less severe hearing loss, such as mild impairments in hearing or hearing loss in only one ear…Learn More >>
  • Movement Disorders: A movement disorder is any movement that impairs function, caused by disrupted communication among the brain, spinal cord and/or peripheral nerves.  Movement disorders range from mild to severe.  Signs or symptoms patients with a movement disorder might experience are too much movement or movement patterns causing abnormal posturing, dystonia (either primary or secondary) or abmusnormal twisting postures, uncontrolled and often jerky movements and rigidity. Gillette’s Complex Movement Clinic treats patients who experience movement disorders, such as dystonia (primary or associated with cerebral palsy), Tardive dyskinesia, athetosis, rigidity or other hyperkinetic movement disorders.
  • Muscular Dystrophy: Muscular dystrophy is the term used to describe a group of diseases of the muscles. In these conditions, the muscle fibers are susceptible to injury. The muscle fibers become progressively weaker. There are over 20 different kinds of muscular dystrophies…Learn More >>
  • Neuromuscular Conditions: Neuromuscular conditions  affect the nerves and/or muscles—typically the peripheral nerves (those outside the brain and spinal cord) and skeletal muscles (such as those in the trunk, arms and legs). The conditions can be static (unchanging) or progressive (growing worse). Most neuromuscular conditions are present at birth, have a genetic component and can affect several generations in a family…Learn More >>
  • Rett Syndrome: Rett syndrome is a rare neurodevelopmental disorder that affects the growth and development of the brain. It occurs in childhood—almost exclusively in girls—and its effects on brain development can cause variable and cascading consequences in areas such as muscle development, walking and communication…Learn More >>
  • Spina Bifida: Spina bifida, a neural tube defect, occurs when an embryo’s spinal cord, surrounding nerves and/or spinal column fail to develop normally during the first month of pregnancy. Spina bifida ranges in severity. In the mildest form, a child might experience no symptoms. In the most severe form, a baby will be born with a portion of the spinal cord outside the body and will have significant lifelong effects…Learn More >>
  • Vision Loss: Vision loss, low vision and visual impairment are terms that are used to describe a wide range of vision problems. Sometimes there is a loss of vision because of problems with the eye, and sometimes vision loss is caused by problems in the brain. This can affect a child’s development in terms of cognitive (thinking), emotional and physical ability. Vision loss is more common in children with other developmental disabilities, as nearly two-thirds of children with vision impairment might also have intellectual disability, cerebral palsy, hearing loss or epilepsy…Learn More >>



These additional terms will help you better understand terms associated with your child’s diagnosis. When words in the definitions are italicized, those words are defined elsewhere in the glossary.

Abduction – Outward movement of a leg or arm away from the body.

Adduction – Inward movement of a leg or arm toward the body.

Ankle foot orthosis (AFO) – A brace that surrounds the ankle and at least part of the foot; used to control the position and motion of the ankle, compensate for weakness or correct deformities.

Assessment (or evaluation) – Process to determine a child’s strengths and weaknesses; includes testing and observations performed by a team of specialists.

Assistive technology – Equipment, such as walkers and crutches, used to compensate for weakness or balance in order to accomplish a particular task, such as walking.

Ataxia – A condition in which damage to the brain results in an unbalanced way of walking (gait); can affect movement, speech, eye movements and the ability to swallow.

Athetosis – Having uncontrolled writhing movements caused by damage to the brain.

Augmentative communication – Use of nonspeech techniques, such as signs, gestures, or pictures, to supplement speech.

Bilateral – Relating to both sides of the body.

Bony deformity – Abnormality in the bone, often caused by the pressure of imbalanced muscles on a growing skeleton.

Brain stem – Portion of the brain between the cerebellum and the spinal cord.

CT (computerized axial tomography) scan – X-ray procedure that uses a computer to combine many X-ray images, creating cross-sectional views and three-dimensional images of the inside of the body.

Cavus – Deformity in which the arch of the foot is abnormally high; usually associated with hindfoot varus-a type of deformity where the heel turns inward.

Cerebellum – Part of the brain that helps coordinate muscle activity and control balance.

Cerebral palsy – Movement and posture disorder resulting from nonprogressive damage to the brain.

Cognitive impairment – Problem with one’s ability to think and/or learn.

Congenital – Condition present at or before birth.

Contracture – Shortening of muscle fibers, which causes a restricted range of motion.

Contraction – Momentary tightening or shortening of muscles.

Cortical visual impairment – Total or partial blindness resulting from injury to the brain’s visual centers; although the eyes can pick up visual information, the brain cannot process and interpret it.

Craniofacial – Pertaining to the skull and the bones of the face.

Crouch gait – Type of walking characterized by a bent posture amongst the hip, knee, and ankle joints (sagittal plane); makes it difficult for a child to maintain upright posture.

Depakene – Valproic acid; an antiepileptic seizure medicine.

Development – Process of growth and learning during which a person acquires skills and abilities.

Developmental disability – An impairment beginning before age 18 that is likely to continue indefinitely and that causes a substantial disability.

Developmental milestone – Developmental goal, such as sitting or using two-word phrases, which health care providers use to measure developmental progress over time.

Diplegia – Type of cerebral palsy in which spasticity primarily affects the legs.

Dystonia – Sustained muscle contractions that cause slow, rhythmic twisting movements or abnormal postures.

Epilepsy – A recurring condition in which abnormal electrical charges in the brain cause seizures.

Equinus – Walking on toes because the calf muscles are shortened or contracted.

Expressive language – The ability to use gestures, words and written symbols to communicate.

Femoral bone (femur) – The long, heavy bone connecting the knee to the hip.

Femoral torsion (femoral ateversion) – Inward twisting of the femur so that the knees and feet turn inward.

Fine motor – Relating to the use of the small muscles of the body, such as those in the face, hands, fingers, feet and toes.

Flexion – Bending of joints.

Floppy – Having weak posture and loose movements.

Foot drop (drop foot) – General term for difficulty lifting the front part of the foot while walking; people with the condition might drag the front of the foot on the ground when they walk.

Foot orthosis – A brace that supports the foot but does not extend above the ankle.

Forefoot – Front third of the foot.

Gait analysis – The use of computers to measure joint motion, force production, muscle activity and sometimes energy exertion when walking.

Gastroesophageal reflux – Condition in which stomach contents are forced back into the esophagus and sometimes the mouth.

Gross motor – Relating to the use of the large muscles of the body; such as those in the legs, arms and abdomen.

Hemiplegia – A type of cerebral palsy in which either the right or left side of the body is affected; the face or trunk can be affected as well.

High tone – Tightness or spasticity of the muscles.

Hindfoot – Back third of the foot.

Hip dislocation – Occurs when the head of the thighbone (femur) slips out of its socket in the pelvis.

Hip subluxation – Incomplete or partial dislocation of the hip joint.

Hypertonia – Increased tension or spasticity of the muscles (high tone).

Hypotonia – Decreased tension of the muscles (low tone).

Individualized Education Program (IEP) – Written plan that describes what services a local school has promised to provide.

Impairment – Decrease in strength, dexterity or ability to use a leg, arm or other body part.

Impaired coordination and balance – Interruption in equilibrium responses and balance mechanisms as a result of damage to the central nervous system.

In-toeing – Walking with the feet turned in (internally rotated).

Intrathecal baclofen pump – A device that is surgically placed under the skin to dispense baclofen into the fluid-filled areas around the spinal cord (known as the intrathecal space) to reduce spasticity. If the catheter is advanced into a patient’s brain, the baclofen is dispensed into a fluid-filled area known as the intraventricular space.

Inversion – When a part of the body turns in.

Knee ankle foot orthosis (KAFO) – Long leg brace of lightweight plastic, with hinges at the knee joint, which supports the entire leg.

Kyphosis – A round-back (hunchback) deformity of the upper spine.

Learning disability – Difficulty processing information in one or more academic areas (reading, writing or math), which interferes with school performance or everyday tasks that require reading, writing, or math skills.

Lever arm dysfunction (LAD) – A bone deformity preventing the muscles that cross or are attached to that bone from functioning normally.

Long-leg sitting – Sitting with legs extended in front of the body.

Long bone torsion – The twisting of the thigh or legbone(s) either outward or inward, which occurs during growth.

Loss of selective motor control – Disruption of the timing, intensity, duration and coordination of voluntary muscle control.

Low tone – Decreased muscle tone.

Lower extremities – Legs.

Manual Ability Classification System (MACS) – One way through which health care providers discuss how people with cerebral palsy use their hands to handle objects in daily activities.

Level I – The person:

      • Handles objects easily and successfully.
      • Experiences limitations in performing manual tasks requiring speed and accuracy. (These limitations don’t interfere with independence in daily activities.)

Level II – The person:

      • Handles most objects, but with a reduced quality and/or speed in achieving tasks and activities.
      • Struggles with some activities; might need alternative ways of doing tasks. (These limitations usually don’t interfere with independence in daily activities.)

Level III – The person:

      • Handles objects with difficulty.
      • Needs help to prepare or adapt activities.
      • Does tasks slowly.
      • Experiences limited success regarding quality and quantity of tasks and activities.
      • Performs activities independently only if they have been set up or adapted.

Level IV – The person:

      • Handles a limited selection of easily managed objects in adapted situations.
      • Performs only parts of activities with effort and limited success.
      • Requires continuous assistance and/or adapted equipment to attempt an activity.

Level V – The person:

      • Cannot handle objects.
      • Experiences severely limited ability to perform even simple actions.
      • Requires total assistance.

Malrotation – Abnormal rotation of a bone that changes the way the muscles are attached.

Midfoot – Middle third of the foot.

Midline – Imaginary reference line down the center of the body, separating left from right.

Motor delay – Slower than normal development of movement skills.

Motor patterns – Ways in which the body and limbs work together to make sequenced movement.

Magnetic resonance imaging (MRI) scan – Medical technique used to see the details of structures inside the body.

Muscle tone – Amount of tension or resistance to movement in a muscle.

Neuroleptic – Medicine that produces changes in the way the nervous system functions.

Neuromotor – Involving both the nerves and the muscles.

Oral motor – Relating to the movement of muscles in and around the mouth.

Orthopedic – Relating to the bones, joints or muscles.

Orthoses – Lightweight devices, made from plastic, leather or metal, which provide stability at the joints or passively stretch the muscles.

Osteotomy – Surgery to cut and realign a bone.

Pes valgus – Foot abnormality in which the foot is flat and the back of the foot is turned outward.

Physical therapy – Evaluation and treatments at helping people improve gross-motor skills, strength and balance. Therapists also recommend, create and customize adaptive equipment, such as power or manual wheelchairs, walkers, and standers.

Posture – Positioning or alignment of the body.

Quadriplegia – Type of cerebral palsy in which the whole body is affected.

Range of motion (ROM) – Degree of movement present at a joint.

Rhizotomy (full name: selective dorsal rhizotomy) – Neurosurgical procedure involving the cutting of selected nerves in the spine to reduce spasticity in muscle groups.

Rigidity – Extremely high muscle tone in any position, combined with very limited movements; muscle resistance occurs throughout the entire range of motion.

Scissoring gait – Crossing legs when standing or being held upright; legs appear to cross each other in a scissors-like movement when walking.

Scoliosis – An abnormal side-to-side curvature of the spine when viewed from the back or front.

Seizure – Involuntary movement or changes in consciousness or behavior brought on by an abnormal burst of electrical activity in the brain.

Selective dorsal rhizotomy – See Rhizotomy.

Sensory integration – Ability of the central nervous system to process and learn from sensations such as sight, touch, sound, smell, taste and movement.

Sensory integration disorders – Central nervous system has difficulty handling information from the senses (sight, touch, sound, smell, taste and movement).

Selective motor control – Ability of the brain to selectively control and coordinate the muscles during activities such as walking, running and reaching for an object.

Speech and language pathology – Services that focus on improving speech and language skills, as well as on improving oral motor abilities (swallowing).

Spasticity – Increased muscle tone (stiff muscles) and a wide range of involuntary muscle spasms (sustained muscle contractions or sudden movements) that result in difficulty moving.

Stimulus – Physical object or environmental event that could affect behavior.

Strabismus – Lack of coordinated eye movement, resulting in crossing and/or wandering eyes.

Subluxation – Partial dislocation of a joint.

Tactile – Relating to touch or the sense of touch.

Toe walking – Walking with the foot and ankle in a toe-down position.

Triplegia – Involvement of both legs and one arm.

Upper extremities – Arms.

Visual-spatial learning disability – Inability to make sense of what one sees; difficulty recognizing complex shapes like letters/numbers, remembering visual patterns, and organizing objects in space (such as understanding a map).

Weakness – Inability to exert as much force with one’s muscles as would be expected given the person’s general physical fitness.

W – sitting – A sitting position where a person’s legs form a “W” shape on the floor (knees bent, legs rotated and facing away from the body).