This study investigates whether near-infrared light therapy can acutely improve ankle dorsiflexion mobility and hamstring flexibility, two factors associated with sports injury risk. Healthy adult students will complete three randomized conditions: a control session, a 10-minute cycling warm-up, and a 10-minute exposure to a red and near-infrared LED panel (MITO LIGHT®). Mobility and flexibility will be assessed before and after each condition using the Knee-to-Wall Test (KWT) and the Active Knee Extension Test (AKET). The study aims to determine whether photobiomodulation may serve as a potential strategy to reduce musculoskeletal injury risk.

This randomized crossover study examines the acute effects of near-infrared LED-based photobiomodulation on ankle dorsiflexion mobility and hamstring flexibility in healthy adults. Each participant will complete three sessions in randomized order: (1) control, (2) 10-minute cycling warm-up, and (3) 10-minute exposure to a red and near-infrared LED panel (MITO LIGHT®), emitting wavelengths range of 800-860 nm. The LED panel will be positioned at 15 cm distance at 100% intensity. Pre- and post-intervention assessments will include the Knee-to-Wall Test (KWT) and the Active Knee Extension Test (AKET). The study is conducted at the Human Movement Laboratory of the University of Aveiro and follows ethical approval from the CEIC-UA. Data will be anonymized and processed according to GDPR. The goal is to determine whether photobiomodulation may contribute to reducing sports injury risk by improving key biomechanical parameters.

Inclusion Criteria:

• Active and healthy university students
• No current pain or injury in the lower limbs
• Ability to perform the Knee-to-Wall Test (KWT) and Active Knee Extension Test (AKET)
• Availability to attend all three sessions with at least 72 hours between assessments
• Signed informed consent

Exclusion Criteria:

• Use of photosensitizing medication currently or within the past 3 weeks (as collected in the medical questionnaire)
• Recent musculoskeletal injury of the lower limbs or any sports-related injury with relevant downtime
• Presence of pain, joint limitation, or any medical condition preventing safe performance of KWT or AKET

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All collected data will be anonymized for statistical analysis and stored securely with restricted access. Therefore, the dataset will be made available upon reasonable request.