The Effect of Physical Fatigue on Lower Limb Functional Performance Tests in a Healthy Population

The Influence of Acute Physical Fatigue on Functional Performance Tests of the Lower Limb in a Healthy Population

The main objective of this project is:

1. To assess the influence of physical fatigue on a return-to-play test battery in a healthy population. In a later stage, these experiments could be carried out in a clinical context (e.g. in an ankle sprain population).

The researchers will use a randomized, placebo controlled, counter-balanced, cross-over design. Twenty healthy subjects will visit the lab 3 times. On the first visit (familiarisation trial), the investigators will collect the participants' characteristics. The participants will also be familiarized to the procedures and materials of the experiment during this first visit. The second and third visit contain the experimental setup and will proceed as follows: first, the participants will fill in a pre-test checklist, a mental fatigue scale (M-VAS) and motivation scale. In the mean time a little blood will be collected from the ear lobe to determine lactate and glucose levels; also, blood pressure will be checked. Next, the subjects will carry out a functional test battery (hop test, vertical jump test, Y-balance test, and a balance reaction-time test). Session rate of perceived exertion (SRPE) is measured to indicate how fatigued the participants feel due to the test battery; also, M-VAS is collected once more, as well blood lactate, glucose and blood pressure. These measures are followed by either a physical fatigue inducing task (Modified 30 seconds Wingate protocol) or time-matched control task (sitting on the bike without pedalling). Afterwards, researchers will collect blood lactate, glucose and blood pressure two times more; participants have to fill in M-VAS (2x), perform the same test battery, and fill in the SRPE scale one more time.

Heart frequency will be measured continuously during the trials.

Inclusion Criteria:

• Healthy (No neurological/cardiorespiratory/psychological/musculoskeletal disorders)
• Male and female
• No medication
• Non-smoker
• Between 18 and 35 years old

Exclusion Criteria:

• Back and/or lower extremity injuries during the past 6 months
• Bone/joint abnormalities
• Dizziness, history of loss of consciousness, any inner ear disorders
• Nervous system disorders or dysfunctions
• Uncorrected eye disorders/dysfunctions
• Illness
• Use of medication or any kind of drugs
• Use of alcohol, caffeine and heavy efforts 24 hours before each trial
• Not eating the same meal the night before and the morning of each experimental trial