human 9 sitting adult 6 female 6 male 6 Humans 5 controlled study 5 Article 4 human experiment 4 Sitting Position 3 normal human 3 supine position 3 Aged 2 Female 2 Male 2 Young Adult 2 aged 2 alertness 2 article 2 body position 2 clinical article 2 daily life activity 2 functional near-infrared spectroscopy 2 leg 2 middle aged 2 physiology 2 pilot study 2 randomized controlled trial 2 shoulder pain 2 standing 2