• Changes in Pressure Pain Thresholds: pressure algometry [ Time Frame: Day-1 (baseline assessment 1), Day-7 (baseline assessment 2, pre exercise), Day-7 (post-exercise), Day-8 (24 hours post-exercise), Day-9 (48 hours post-exercise), Day-10 (72 hours post-exercise), Day-14 (1-week post-exercise). ]
  Changes in pressure pain thresholds will be determined with pressure algometry bilaterally over the forearm, leg and shoulder. Pressure Pain Threshold is defined as the exact time point where the pressure is first being perceived at painful.
• Changes in subjective perception of pain and recovery: Likert Scale [ Time Frame: Day-1 (baseline assessment 1), Day-7 (baseline assessment 2, pre exercise), Day-7 (post-exercise), Day-8 (24 hours post-exercise), Day-9 (48 hours post-exercise), Day-10 (72 hours post-exercise), Day-14 (1-week post-exercise). ]
  A modified 7-item Likert Scale for pain ("0" No pain - "6" Severely disabling pain) and a visual analogue scale (0-10 cm) for self-recovery perception will be filled up to show subjective perception along the follow-up period.

• Changes in Pressure Pain Thresholds: pressure algometry [ Time Frame: Day-1 (baseline assessment 1), Day-7 (baseline assessment 2, pre exercise), Day-7 (post-exercise), Day-8 (24 hours post-exercise), Day-9 (48 hours post-exercise), Day-10 (72 hours post-exercise), Day-14 (1-week post-exercise). ]
  Changes in pressure pain thresholds will be determined with pressure algometry bilaterally over the forearm, leg and shoulder. PPT is defined as the exact time point where the pressure is first being perceived at painful.
• Changes in subjective perception of pain and recovery: Likert Scale [ Time Frame: Day-1 (baseline assessment 1), Day-7 (baseline assessment 2, pre exercise), Day-7 (post-exercise), Day-8 (24 hours post-exercise), Day-9 (48 hours post-exercise), Day-10 (72 hours post-exercise), Day-14 (1-week post-exercise). ]
  A modified 7-item Likert Scale for pain ("0" No pain - "6" Severely disabling pain) and a visual analogue scale (0-10 cm) for self-recovery perception will be filled up to show subjective perception along the follow-up period.

• Changes in mechanical properties of the muscle [ Time Frame: Day-1 (baseline assessment 1), Day-7 (baseline assessment 2, pre exercise), Day-7 (post-exercise), Day-8 (24 hours post-exercise), Day-9 (48 hours post-exercise), Day-10 (72 hours post-exercise), Day-14 (1-week post-exercise). ]
  Changes in mechanical properties of the muscle will be determined with myotonometer bilaterally over the forearm.
• Changes in manual dexterity [ Time Frame: Day-1 (baseline assessment 1), Day-7 (baseline assessment 2, pre exercise), Day-7 (post-exercise), Day-8 (24 hours post-exercise), Day-9 (48 hours post-exercise), Day-10 (72 hours post-exercise), Day-14 (1-week post-exercise). ]
  Changes in manual dexterity of both upper limbs will be assessed by the Nine Hole Peg Test. Participants will had to place 9 pegs in a specifically designed board as fast as possible.
• Changes in maximal isometric force [ Time Frame: Day-1 (baseline assessment 1), Day-7 (baseline assessment 2, pre exercise), Day-7 (post-exercise), Day-8 (24 hours post-exercise), Day-9 (48 hours post-exercise), Day-10 (72 hours post-exercise), Day-14 (1-week post-exercise). ]
  Changes in wrist extensors maximal isometric strength will be assessed with hand-held dynamometry.
• Changes in active range of motion [ Time Frame: Day-1 (baseline assessment 1), Day-7 (baseline assessment 2, pre exercise), Day-7 (post-exercise), Day-8 (24 hours post-exercise), Day-9 (48 hours post-exercise), Day-10 (72 hours post-exercise), Day-14 (1-week post-exercise). ]
  Changes in active range of motion of the wrist will be assessed in both sides using a digital inclinometer.
• Level of catastrophizing [ Time Frame: Day-1 (baseline), Day-14 (1-week post-exercise). ]
  Punctuation obtained in Pain Catastrophizing Scale (PCS). It comprises 13 items which focus on thoughts and feelings encountered while experiencing pain. Each item is scored from 0 (not at all) to 4 (all the time) with a total PCS score range from 0-52 points, where higher scores indicating higher levels of pain catastrophizing.

• Changes in mechanical properties of the muscle [ Time Frame: Day-1 (baseline assessment 1), Day-7 (baseline assessment 2, pre exercise), Day-7 (post-exercise), Day-8 (24 hours post-exercise), Day-9 (48 hours post-exercise), Day-10 (72 hours post-exercise), Day-14 (1-week post-exercise). ]
  Changes in mechanical properties of the muscle will be determined with myotonometry bilaterally over the forearm.
• Changes in manual dexterity [ Time Frame: Day-1 (baseline assessment 1), Day-7 (baseline assessment 2, pre exercise), Day-7 (post-exercise), Day-8 (24 hours post-exercise), Day-9 (48 hours post-exercise), Day-10 (72 hours post-exercise), Day-14 (1-week post-exercise). ]
  Changes in manual dexterity of both upper limbs will be assessed by the Nine Hole Peg Test. Participants will had to place 9 pegs in a specifically designed board as fast as possible.
• Changes in maximal isometric force [ Time Frame: Day-1 (baseline assessment 1), Day-7 (baseline assessment 2, pre exercise), Day-7 (post-exercise), Day-8 (24 hours post-exercise), Day-9 (48 hours post-exercise), Day-10 (72 hours post-exercise), Day-14 (1-week post-exercise). ]
  Changes in wrist extensors maximal isometric strength will be assessed with hand-held dynamometry.
• Changes in active range of motion [ Time Frame: Day-1 (baseline assessment 1), Day-7 (baseline assessment 2, pre exercise), Day-7 (post-exercise), Day-8 (24 hours post-exercise), Day-9 (48 hours post-exercise), Day-10 (72 hours post-exercise), Day-14 (1-week post-exercise). ]
  Changes in active range of motion of the wrist will be assessed in both sides using a digital inclinometer.
• Level of catastrophizing [ Time Frame: Day-1 (baseline), Day-14 (1-week post-exercise). ]
  Punctuation obtained in Pain Catastrophizing Scale (PCS). It comprises 13 items which focus on thoughts and feelings encountered while experiencing pain. Each item is scored from 0 (not at all) to 4 (all the time) with a total PCS score range from 0-52 points, where higher scores indicating higher levels of pain catastrophizing.

The aim of this study is to determine how is the normalization process of sensory (pressure pain thresholds, subjective pain sensation, self-recovery perception), motor (maximal isometric strength, active range of motion, manual dexterity) and tissue (myotonometer) variables after an experimental pain model in the extensor forearms muscles, by delayed onset muscle soreness after an eccentric exercise in healthy subjects. This way will be possible to establish 1) if there are differences in the time of normalization for each variable; 2) if there is a correlation between each variable and self-recovery perception.

Seven assessment sessions are performed in a 14-days period. Day 0 (baseline assessment 1), Day 7 (baseline assessment 2, pre exercise), Day 7 (post exercise), Day 8 (24-hours post exercise), Day 9 (48-hours post exercise), Day 10 (72-hours post exercise), Day 14 (1-week post exercise).

• Musculoskeletal Pain
• Healthy
• Delayed Onset Muscle Soreness

Inclusion Criteria:

• Adult healthy subjects of both sexes.
• Age: 18-50.
• Being free from any pain specific to the upper limb and/or in general.

Exclusion Criteria:

• History of acute or chronic painful condition in the previous 3 months.
• Regular medication intake for any reason.
• History of severe injury in the upper extremity (e.i. fracture).
• Prior surgery in the upper limb.
• Diagnosed of any chronic pain syndrome (fibromyalgia, migraine, etc.) or severe disease.

Withdrawal Criteria:

• Being involved in new physical stimulus, which volunteer is not used to.
• Micronutrient supplementation intake.
• NSAIDs or other medication intake.