Terms
Defined.
Key terminology used in EchoDepth Sport and sport emotional intelligence.
Action Unit (AU)
One of 46 individual muscle movements defined in the Facial Action Coding System (FACS). Each AU corresponds to a specific facial muscle or muscle group. EchoDepth Sport tracks 44 of the 46 defined AUs in real time.
Arousal
One of the three dimensions in VAD emotional modelling. Arousal measures the activation or energy level of an emotional state — from calm/suppressed (low arousal) to excited/activated (high arousal). A primary fatigue and readiness marker in EchoDepth Sport.
Dominance
One of the three dimensions in VAD emotional modelling. Dominance measures the degree of control, confidence, or agency in an emotional state — from overwhelmed/anxious (low dominance) to in control/confident (high dominance). A pressure response indicator.
Duchenne Smile
A genuine smile involving both the zygomatic major muscle (AU 12, lip corner puller) and the orbicularis oculi muscle (AU 6, cheek raiser). Distinguished from a social smile which activates AU 12 alone. Used by EchoDepth Sport as an authenticity marker.
FACS (Facial Action Coding System)
The peer-reviewed scientific standard for measuring facial movement, developed by psychologists Paul Ekman and Wallace Friesen in 1978. FACS defines 46 Action Units corresponding to individual facial muscle movements. EchoDepth Sport's detection engine is FACS-based.
HIA (Head Injury Assessment)
The concussion assessment protocol used in rugby union. EchoDepth Sport's concussion protocol is designed to supplement the HIA — providing medical staff with objective, timestamped AU divergence data at the point of assessment.
Individual Baseline
Each player's unique emotional profile, calibrated over their first 3–4 weeks on the EchoDepth Sport platform. Deviations are flagged relative to each player's personal norm — not a population average. The individual baseline is the foundation of EchoDepth Sport's alerting system.
Micro-Expression
A very brief, involuntary facial expression that reveals an emotion a person is trying to conceal or suppress. Micro-expressions last between 1/25 and 1/5 of a second. EchoDepth Sport's high-frequency AU detection captures micro-expression patterns.
VAD (Valence, Arousal, Dominance)
A three-dimensional model of emotional state. Valence measures positive/negative quality. Arousal measures activation level. Dominance measures degree of control. Together they provide a comprehensive emotional state model that EchoDepth Sport uses to interpret AU patterns.
Valence
One of the three dimensions in VAD emotional modelling. Valence measures whether an emotional state is positive or negative — from negative/unpleasant (low valence) to positive/pleasant (high valence). A primary indicator of emotional wellbeing in EchoDepth Sport.
Welfare Officer
A club staff member responsible for the mental health, wellbeing, and safeguarding of players. EchoDepth Sport's welfare dashboard and alerting system is specifically designed to support welfare officers with continuous, objective data.