CAFFEINE DOES NOT AFFECT POSITIONING FACTORS BUT DOES AFFECT FORCE REPLICATION FACTORS
Henry, S., & Gamble, J. (2008). The effects of caffeine on proprioception. ACSM 55th Annual Meeting Indianapolis, Presentation Number 2038.
This study investigated the effects of caffeine on muscle/joint kinesthesia (proprioception). College-aged Ss (N = 11) completed placebo and experimental (caffeine ingestion, 6 mg/kg) conditions. Ss were pre-tested, ingested caffeine or placebo, and post-tested 60 minutes after ingestion. Using electrogoniometers, proprioception was assessed by the S’s ability to actively replicate a target (a passively-presented reference) angle and velocity of knee flexion and extension. Force gradation, the ability to produce a target sub-maximal isometric force (25%, 50%, or 75% maximal voluntary isometric contraction), was assessed using a handgrip force transducer.
There were no differences for knee joint angle replication and joint velocity. There was a detrimental difference in isometric grip force gradation as indicated by increased error.
Implication. Caffeine had no effect on the ability to actively replicate a target knee joint angle or joint velocity of a passively-presented reference target. However, caffeine negatively affected the ability to scale submaximal force generation with the hands.