Glossary of Terms Commonly Used About Larsen Syndrome

Many thanks to Michael Klein, DO from Albuquerque, NM for his assistance in compiling and defining the terms below:

abduction–  the movement of a limb or other part of the body outward from the body

acetabulum – the socket where the hip bone (femur) fits into the pelvic bones; if this socket is too shallow, the femur can easily come out of the joint the radius is the smaller bone of the forearm on the same side as the thumb; the ulna is the larger bone in the forearm on the same side as the pinky finger

ACL the anterior cruciate ligament (ACL) keeps the shin bone (tibia) in place

ADLactivity of daily living such as eating, bathing, or  dressing

adduction–  the movement of a limb or other body part  inward to the body

apneanot breathing for an extended period of time (more than 20 seconds) during sleep

arthritisinflammation of a joint

arthrogryposisa disorder of the joints that is not inherited but rather caused by an intrauterine (in the womb) developmental abnormality.

atrial septal defect – a hole in the upper chambers of the heart (right and left atriums)

audiologist– professional who specializes in the treatment of hearing loss and/or tinnitus-  commonly with hearing aides

auricle part of the outer ear including the lobe

autosomesthe term for the first 22 pairs of chromosomes

bronchi – the main passageway into the lungs

cardiovascular – pertaining to the heart heart and blood vessels

carpal bones – bones of the wrist of which there are normally eight

cartilage– flexible elastic tissue, connecting the joins between bones, the rib cage, the ear, the nose, the bronchial tubes, the intervertebral discs, and many more other body components. It is not as hard and rigid as bone, but it is stiffer and less flexible than muscle

cervical kyphosis – an abnormal curvature of the spine in the neck; this can lead to compression of the spinal cord with resultant serious complications

chromosomes–  the carriers of human genetic material or DNA

cleft lip and/or palate – a gap in the upper lip or the roof of the mouth that usually requires surgical repair. Uncorrected, these deformities can lead to speech problems and frequent ear infections

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photo credit:

club foot – a foot that is turned in or out in an abnormal position; often treated with serial casting

cochleapart of hearing system where nerve cells are located which allow us to hear sounds

congenital – present at birth

contractures – muscles and tendons that are abnormally tight; can lead to a deformity of an extremity

cylindrical – round in shape

depressed nasal bridgethe top of the nose is more flat than usual and closer to the face

dislocation – a bone that is outside of the normal joint space 

equinovalgus –  a foot that curves outwards

equinovarus – a foot that curves inwards

fibula–  smaller leg bone below the knee on the outside of the leg

fixator – a type of orthopedic hardware place surgically to hold bones in place while they heal

frontal bossing – a forehead that is more prominent than usual

femur – the thigh bone

genetics –  the study of human inheritance patterns

halo – a type of brace that is attached to the skull and a vest to stabilize the upper spine after an accident or surgery

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photo credit:

humerus – the bone between the shoulder and the elbow

hyperacusis–  having a reduced tolerance and/or  increased sensitivity to everyday sounds. People who suffer from this condition often complain of living in a world in which the volume is too loud

hypermobility – joints are described as hypermobile when they allow more movement than is considered typical ( i.e. pulling the thumb backwards)

hypertelorism – eyes that are wider spaced apart than usual

hypertonia – muscles which are too rigid or “tight”

hypotelorism – eyes that are more close together than usual

hypotonia – muscles which are weak or “floppy”

incus–  bone of the middle ear commonly known as the hammer

karotypea picture of an individual’s complete set of chromosomes

kyphoscoliosis – a combination of scoliosis and kyphosis of the spinal column

kyphosis – a condition where the upper back protrudes more than normal

ligament a short band of tough, flexible, fibrous connective tissue that connects two bones or cartilages or holds together a joint

lordosis – “The small” or lower part of the back above the hips which curves inwardly too far resulting in pain and/or nerve damage

malleus–  bone of the middle ear commonly known as the anvil

malar flattening–  cheek bones which are flatter than normal

metacarpal bones – the five bones that connect the wrist to the fingers

metatarsal bones – the five bones that connect the tarsal bones to the toes 

muscle–  a band or bundle of fibrous tissue that has the ability to contract, producing movement in or maintaining the position of parts of the body

neurologist medical doctor who specializes in disorders of the nervous system which  includes the brain, spinal cord, nerves, and sense organs and receives, interprets, and responds to stimuli from inside and outside the body

occupational therapistknown as an OT;  treat injured, ill, or disabled patients to  help these patients develop, recover, and improve the skills needed for daily living and working

orthopedist medical doctor who specializes in disorders of the musculoskeletal system (bones, joints, etc)

orthoticsmore commonly known as braces.  An AFO is a brace for the ankle (bottom right) a KAFO is a brace for the knee and ankle (bottom left),  and a HKFO is a brace for the hips, knees, and ankles








orthotistcertified professional who makes orthotics more commonly known as braces

ossicles – collective term for bones of the middle ear

osteoarthritis–  degeneration of joint cartilage and the underlying bone, most common from middle age onward. It causes pain and stiffness, especially in the hip, knee, and thumb joint

osteoporosis a medical condition in which the bones become brittle and fragile from loss of tissue; there is an increased risk of bone fractures

otitisinflammation or infection of the ear

otitis externainfection of the outer ear more commonly known as swimmer’s ear

otitis media infection of the middle ear

otolaryngologist medical doctor more commonly known as an ENT; specializes in disorders of the ear, nose, and/or throat

physical therapist–   known as PTs; are licensed health care professionals who can help patients reduce pain and improve or restore mobility – in many cases without expensive surgery and often reducing the need for long-term use of prescription medications and their side effects

plastic surgeona medical doctor who performs cosmetic and reconstructive procedures for face and body; often the specialist to repair a cleft lip and/or palate

pulmonologistmedical doctor who specializes in disorders of the lungs and other organs related to the respiratory system which controls breathing

respiratory therapist cares for patients who have trouble breathing—for example, from a chronic respiratory disease (such as asthma or emphysema), or after an accident or surgery

 tinnitus  – commonly referred to as ringing in the ears;  the sensation of hearing ringing, buzzing, hissing, chirping, whistling, or other sounds. The noise can be intermittent or continuous, and can vary in loudness

patella – commonly referred to as the knee cap

pediatricianmedical doctor who specializes in the care of children who are ill; another extremely important role of this doctor is to track the growth and development of children and refer to specialists if a problem is suspected

phalanges – finger bones

phalanx – a single bone in a finger or toe

polydactyly – having extra fingers and/or toes

prosthetican artificial limb

prosthetista certified professional who makes custom fit artificial limbs

radiussmall bone in the forearm on same side as the thumb

respiratory – pertaining to the organs involved in breathing

scoliosis – a sideways curvature of the spine at any level.  Could be labeled as levo ( left) or dextro (right); can lead to pain and/or respiratory complications

spatulate thumb – a thumb that is flatter and broader than usual


speech pathologist a specialist trained to treat delays in speech; also treats other speech disorders such as stuttering and swallowing disorders caused by a birth defect such as cleft palate

stapes bone of the middle ear commonly known as the stirrup

subluxation – a bone that is not completely dislocated as it is only part -way out of the joint space

syndactyly –  term that describes when fingers and/or toes are fused together.

syndrome – a constellation of signs and symptoms that are recognizable as a disorder

tarsal bones – the seven bones that comprise the back of the heel and the back of the foot

tendon–  a flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to a bone

tibia– larger bone in the foreleg below the knee on the the side of the big toe

trachea commonly referred to as the windpipe;   a large membranous tube reinforced by rings of cartilage, extending from the larynx to the bronchial tubes and conveying air to and from the lungs

tracheomalacia – a condition characterized by flaccidity (lacking firmness) of the tracheal support cartilage which leads to tracheal collapse especially when increased airflow is demanded.  If this flaccidity exists further down to the the lungs, it is referred to as bronchotracheomalacia

trisomythe abnormal presence of an extra chromosome which usually causes Down’s Syndrome, (also called Trisomy 21) , a condition in which extra genetic material causes delays in the way a child develops- both mentally and physically

ulna larger bone in the forearm located on the same side as the pinky finger

urogenital – pertaining to the urinary and reproductive system

ventricular septal defect – a hole in the bottom chambers of the heart (right and left ventricles)