Knemometry
Encyclopedia
Knemometry denotes a technical device for measuring the distance
between knee
and heel
of a sitting child
or adolescent. Knemometric measurements show a measurement error of less than 160 µm (0.16 mm) and enable illustrating growth at intervals of few weeks (short-term growth).
. It is being practiced since and used for basic research
in growth and the treatment of growth disorders. Hermanussen
introduced the mini-knemometer for accurate growth measurements of prematures and newborn infants. Mini-knemometry determines the lower leg length with an accuracy of less than 100 µm (0.1 mm). This enables substantiating growth within 24 hours. In an animal model, the technique was used to investigate the effects of steroids and growth hormone
on short-term growth. These studies were an important prerequisite for improving growth therapies.
term "short-term growth" denotes growth characteristics that become evident when measurements are being performed within intervals of less than one year (e.g. monthly, weekly or even daily). Mainly knemometry has been used for this purpose, but also very frequent measurements using conventional devices for height measurements.
Short-term growth consists of small growth spurts (mini growth spurts). In the human neonate, these spurts occur at intervals of 2 to 10 days, and they reach maximum velocities of up to 0.2 mm per hour at the lower leg. Growth hormone therapies have been shown to significantly alter the dynamics of short-term growth. Catch-up growth (compensatory growth after periods of growth impairment due to illness, starvation and other unfavourable conditions) is characterised by repetitive series of broadened mini growth spurts.
Distance
Distance is a numerical description of how far apart objects are. In physics or everyday discussion, distance may refer to a physical length, or an estimation based on other criteria . In mathematics, a distance function or metric is a generalization of the concept of physical distance...
between knee
Knee
The knee joint joins the thigh with the leg and consists of two articulations: one between the fibula and tibia, and one between the femur and patella. It is the largest joint in the human body and is very complicated. The knee is a mobile trocho-ginglymus , which permits flexion and extension as...
and heel
Heel
In human anatomy, the heel is the prominence at the posterior end of the foot. It is based on the projection of one bone, the calcaneus or heel bone, behind the articulation of the bones of the lower leg.- Human anatomy :...
of a sitting child
Child
Biologically, a child is generally a human between the stages of birth and puberty. Some vernacular definitions of a child include the fetus, as being an unborn child. The legal definition of "child" generally refers to a minor, otherwise known as a person younger than the age of majority...
or adolescent. Knemometric measurements show a measurement error of less than 160 µm (0.16 mm) and enable illustrating growth at intervals of few weeks (short-term growth).
The device
Ignaz Maria Valk developed this technique in 1983 in Nijmegen/NetherlandsNetherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
. It is being practiced since and used for basic research
Basic Research
Basic Research is an herbal supplement and cosmetics manufacturer based in Salt Lake City, Utah that distributes products through a large number of subsidiaries. In addition, their products are sold domestically and internationally through a number of high-end retailers. Dennis Gay is the...
in growth and the treatment of growth disorders. Hermanussen
Michael Hermanussen
Michael Hermanussen is a German pediatrician and professor at the University of Kiel. He is known for his work on growth and nutrition.-Life:...
introduced the mini-knemometer for accurate growth measurements of prematures and newborn infants. Mini-knemometry determines the lower leg length with an accuracy of less than 100 µm (0.1 mm). This enables substantiating growth within 24 hours. In an animal model, the technique was used to investigate the effects of steroids and growth hormone
Growth hormone
Growth hormone is a peptide hormone that stimulates growth, cell reproduction and regeneration in humans and other animals. Growth hormone is a 191-amino acid, single-chain polypeptide that is synthesized, stored, and secreted by the somatotroph cells within the lateral wings of the anterior...
on short-term growth. These studies were an important prerequisite for improving growth therapies.
The measurement of short-term growth
The auxologicalAuxology
Auxology, sometimes called Auxanology , is a meta-term covering the study of all aspects of human physical growth...
term "short-term growth" denotes growth characteristics that become evident when measurements are being performed within intervals of less than one year (e.g. monthly, weekly or even daily). Mainly knemometry has been used for this purpose, but also very frequent measurements using conventional devices for height measurements.
Short-term growth consists of small growth spurts (mini growth spurts). In the human neonate, these spurts occur at intervals of 2 to 10 days, and they reach maximum velocities of up to 0.2 mm per hour at the lower leg. Growth hormone therapies have been shown to significantly alter the dynamics of short-term growth. Catch-up growth (compensatory growth after periods of growth impairment due to illness, starvation and other unfavourable conditions) is characterised by repetitive series of broadened mini growth spurts.