Jump Test

The Jump Test is a method to measure lower-limb muscle power, as well as coordination of lower and upper extremities, by jumping as high as possible. Jumping height is calculated from flight time.
The Jump Test was performed in 32,000 able Lifelines participants aged 8 years and older during 2A Visit 1 (section: physical state).

Protocol

The 5-min jumptest is performed on a Chronojump Contactmat (40 by 60 cm) chronojump_manual.pdf.
Participants take off their shoes if the heels are higher than 2 cm. Research nurse asks the participant after any contraindications and makes sure the participant is able to make a two legged vertical jump.

Participant receives instructions:

The research nurse demonstrates the jump at half speed. The participant first makes a test jump on half speed.
The participant makes 3 repeated vertical jumps, separated by a minimum of 30 seconds rest.
All flight times are recorded.

Contra-indications

Participants could not participate in the Jump test if they were given the advice by a GP or specialist to not perform any pressurizing activities, for example after:

… or if they should not perform any strenuous exercise for other reasons:

Validation

The gold standard for measuring countermovement jumps is with a force platform. The Chronojump was validated against a regular force platform in thirty recreationally active adults 1).
The Bland-Altman plot showed that Chronojump underestimated countermovement height by 5.46 cm. Previously it was shown that reliability was greater for participants more accustomed ot strength training.

Rationale for use in Lifelines

Mechanography measures muscle power and peak-force, evaluates coordination and muscular function, and characterizes the muscle-bone relation.
The close functional relationship between muscle and bone observed throughout growth involves mechanical and biochemical crosstalk and suggests a prominent role of lean mass and muscle function on peak-bone acquisition. DXA scans can provide an accurate and precise quantification of lean mass, but do not provide information regarding muscle strength or quality.
Using a jumping-test-based mechanography, one can measure several parameters of muscular function and motion and also study the muscle-bone unit integrity. The loading imposed by muscles stimulates growing bones to adapt their geometry and mineral content to preserve, or increase, bone strength, which when impaired, predisposes to fracture (Frost’s mechanostat theory).
In elderly people, the mechanograph can be setup on its geriatric version based on the chair-rising test. The chair-rising test is a widely used measurement of lower body strength and falling risk in frail and elderly populations.
The machine is also very suited to measure muscle function and motion in children using the jumping plate. It also allows evaluation of the neuromotor function in both children and adults by measuring kinetic parameters where aspects such as equilibrium, coordination and proprioperception can be evaluated. 2) 3) 4)

Variables

The following variables were collected during the Jump Test:

English Dutch Code Variable Assessment Age
jump test measured jumptest uitgevoerd? jumptest_performed_all_m_1 jumpond 2A Visit 1 8+
if not, reason: / jump test measured indien nee, reden: / jumptest uitgevoerd jumptest_performed_all_m_1_a jumpreden 2A Visit 1 8+
time of flight 1 (s) vluchttijd 1 (s) jumptest_flighttime_all_m_1 tf1 2A Visit 1 8+
time of flight 2 (s) vluchttijd 2 (s) jumptest_flighttime_all_m_2 tf2 2A Visit 1 8+
time of flight 3 (s) vluchttijd 3 (s) jumptest_flighttime_all_m_3 tf3 2A Visit 1 8+
1)
Stanton R, Doering TM, Macgregor C, Borges N, Delvecchio L. Validity of a contact mat and accelerometric system to assess countermovement jump from flight time. Measurement in physical eduation and exercise science. 2018
2)
Veilleux LN, Rauch F. Reproducibility of jumping mechanography in healthy children and adults. J Musculoskelet Neuronal Interact 2010;10(4):256-66.
3)
Fricke O, Stabrey A, Tutlewski B, Schoenau E. Mechanographic analyses in pediatrics: allometric scaling of 'peak jump force' and its relationship to 'maximal isometric grip force' in childhood and adolescence. Klin Padiatr 2009;221(7):436-9.
4)
Dionyssiotis Y, Galanos A, Michas G, Trovas G, Lyritis GP. Assessment of musculoskeletal system in women with jumping mechanography. Int J Womens Health 2009;1:113-8