A novel method for accurate division of the gait cycle into seven phases using shank angular velocity.

BACKGROUND: Accurate detection of gait events is crucial for gait analysis, enabling the assessment of gait patterns and abnormalities. Inertial measurement unit (IMU) sensors have gained traction for event detection, mainly focusing on initial contact (IC) and toe-off (TO) events. However, effective detection of other key events such as heel rise (HR), feet adjacent (FA), and tibia vertical (TBV) is essential for comprehensive gait analysis. RESEARCH QUESTION: Can a novel IMU-based method accurately detect HR, TO, FA, and TBV events, and how does its performance compare with existing methods? METHODS: We developed and validated an IMU-based method using cumulative mediolateral shank angular velocity (CSAV) for event detection. A dataset of nearly 25,000 gait cycles from healthy adults walking at varying speeds and footwear conditions was used for validation. The method's accuracy was assessed against force plate and motion capture data and compared with existing TO detection methods. RESULTS: The CSAV method demonstrated high accuracy in detecting TO, FA, and TBV events and moderate accuracy in HR event detection. Comparisons with existing TO detection methods showcased superior performance. The method's stability across speed and shoe variations underscored its robustness. SIGNIFICANCE: This study introduces a highly accurate IMU-based method for detecting gait events needed to divide the gait cycle into seven phases. The effectiveness of the CSAV method in capturing essential events across different scenarios emphasizes its potential applications. Although HR event detection can be further improved, the precision of the CSAV method in TO, FA, and TBV detection advance the field. This study bridges a critical gap in IMU-based gait event detection by introducing a method for subdividing the swing phase into its subphases. Further research can focus on refining HR detection and expanding the method's utility across diverse gait contexts, thereby enhancing its clinical and scientific significance.

Gyroscope sensor data of shank motion during normal and barefoot walking.

In recent years, shank angular velocity (SAV) has emerged as a valuable tool for accurate temporal gait analysis and motion pattern assessment. To explore SAV among healthy subjects and its capability to distinguish differences between walking conditions, three-dimensional SAV data was measured with a gyroscope sensor during normal and barefoot walking. The resulting dataset contains measurement data from 58 healthy adult subjects aged 19 to 75 years. A single gyroscope was positioned on the lateral side of both shanks just above the lateral malleolus. The data collection involved the subjects walking a 10 m distance three times, both wearing shoes and barefoot. The subjects were instructed to walk with their own natural walking velocity, and each walk began from a stationary position. The dataset has the potential to provide information on how height and weight affect gait kinematics and how barefoot walking differ from walking with shoes. The data also supports designing the collection protocol for more extensive datasets of IMU-based shank motion during gait.

Increasing self-other similarity modulates ethnic bias in sensorimotor resonance to others' pain.

The tendency to simulate the pain of others within our own sensorimotor systems is a vital component of empathy. However, this sensorimotor resonance is modulated by a multitude of social factors including similarity in bodily appearance, e.g. skin colour. The current study investigated whether increasing self-other similarity via virtual transfer to another colour body reduced ingroup bias in sensorimotor resonance. A sample of 58 white participants was momentarily transferred to either a black or a white body using virtual reality technology. We then employed electroencephalography to examine event-related desynchronization (ERD) in the sensorimotor beta (13-23 Hz) oscillations while they viewed black, white and violet photorealistic virtual agents being touched with a noxious or soft object. While the noxious treatment of a violet agent did not increase beta ERD, amplified beta ERD in response to black agent's noxious vs soft treatment was found in perceivers transferred to a black body. Transfer to the white body dismissed the effect. Further exploratory analysis implied that the pain-related beta ERD occurred only when the agent and the participant were of the same colour. The results suggest that even short-lasting changes in bodily resemblance can modulate sensorimotor resonance to others' perceived pain.

The Positive Effects of Trait Emotional Intelligence during a Performance Review Discussion - A Psychophysiological Study.

Performance review discussions of real manager-subordinate pairs were examined in two studies to investigate the effects of trait emotional intelligence (EI) on dyad member's felt and expressed emotions. Altogether there were 84 managers and 122 subordinates in two studies using 360 measured and self-reported trait EI. Facial electromyography, and frontal electroencephalography (EEG) asymmetry were collected continuously. Manager's high trait EI was related to increased positive valence emotional facial expressions in the dyad during the discussions. The managers also had more EEG frontal asymmetry indicating approach motivation, than the subordinates. In addition, actor and partner effects and actor × partner interactions, and interactions between the role and actor or partner effect of trait EI were observed. Both actor and partner trait EI were related to more positive self-reported emotional valence. The results imply that trait EI has a role in organizational social interaction.

The role of personality in dyadic interaction: A psychophysiological study.

Psychophysiological activity was recorded during development discussions of 44 manager-subordinate pairs to examine the effects of the Big Five personality traits Extraversion and Conscientiousness, and personality similarity during dyadic social interaction. Facial electromyography and frontal electroencephalography (EEG) asymmetry were collected continuously during the 30-min discussions. Different actor and partner effects and Actor×Partner interactions were observed. Matching levels of Extraversion led to higher periocular muscle activity, indicating positive valence emotional expressions. The results are discussed considering similarity attraction theories.

Increased oscillatory theta activation evoked by violent digital game events.

The authors examined electroencephalographic (EEG) oscillatory responses to two violent events, the player character wounding and killing an opponent character with a gun, in the digital game James Bond 007: NightFire. EEG was recorded from 25 (16 male) right-handed healthy young adults. EEG data were segmented into one 1-s baseline epoch before each event and two 1-s epochs after event onset. Power estimates (microV(2)) were derived with the fast Fourier transform (FFT) for each artefact free event. Both of the studied events evoked increased occipital theta (4-6Hz) responses as compared to the pre-event baseline. The wounding event evoked also increased occipital high theta (6-8Hz) response and the killing event evoked low alpha (8-10Hz) asymmetry over the central electrodes, both relative to the pre-event baseline. The results are discussed in light of facial electromyographic and electrodermal activity responses evoked by these same events, and it is suggested that the reported EEG responses may be attributable to affective processes related to these violent game events.

Oscillatory brain responses evoked by video game events: the case of super monkey ball 2.

Electroencephalography (EEG) was recorded while the subjects played a video game where the player had to steer a monkey into a goal while collecting bananas for extra points and had to avoid falling off the edge of the game board. Each of these three studied events evoked differential EEG oscillatory changes. Picking up bananas evoked decreased theta activation on central electrodes, decreased high alpha activation on frontal electrodes, and increased beta activation on frontal electrodes. Falling off the game board evoked decreased central theta activation and increased fronto-central beta activation. Reaching the goal evoked increased theta activation on parietal electrodes, increased low alpha activation on frontal electrodes, increased high alpha activation on frontal, central, and parietal electrodes, and increased beta activation on frontal and central electrodes. It is suggested that the EEG oscillations evoked by picking up bananas reflect increased cortical activation and arousal; the oscillations evoked by falling off the edge of the game board reflect motor functions; and the oscillations evoked by reaching the goal reflect a relaxed state. Thus, EEG may turn out to be a valuable tool when examining psychological responses to video game events.