• Changes in Pressure Pain Thresholds [ Time Frame: Baseline, 48 hours, 96 hours, 1 week ]
  Changes in pressure pain thresholds (PPT) will be determined with pressure algometry bilaterally over the leg and shoulder. PPT is defined as the exact time point where the pressure is first being perceived at painful.
• Changes in active knee extension test [ Time Frame: Baseline, 48 hours, 96 hours, 1 week ]
  Changes in range of motion (°; degrees) will be assessed in both sides using the active knee extension (AKE) test. AKE test: subject is lying prone with hip and knee flexed at 90°. Then, maximal knee extension is performed.
• Changes in knee-flexors maximal isometric muscle strength [ Time Frame: Baseline, 48 hours, 96 hours, 1 week ]
  Changes in knee-flexors maximal isometric strength (Newton) will be assessed by using a hand-held dynamometer.
• Electromyography (EMG) measurement during the tests [ Time Frame: Baseline, 48 hours, 96 hours, 1 week ]
  Electromyography values will be taken from hamstrings during the performance of gait analysis and dynamometry
• Changes in thermography on hamstrings areas [ Time Frame: Baseline, 48 hours, 96 hours, 1 week ]
  A thermography image will be taken every day of assessment. Changes in colour pixels will be analysed to determine temperature changes.
• Changes in static and dynamic plantar pressure measurement [ Time Frame: Baseline, 48 hours, 96 hours, 1 week ]
  Changes in static and dynamic plantar pressure measurement will be performed in every session by using a pressure platform.
• Changes in subjective perception of pain and impairment: Two questionnaire (Modified 7-item Likert Scales) [ Time Frame: 48 hours, 96 hours, 1 week ]
  Two questionnaires (Modified 7-item Likert Scales) are filled up by the subject to show subjective perception of pain related to movement along the recovery period. Scale of pain intensity, from 0 (no pain) to 6 (higher pain intensity). Scale of functional impairment, from 0 (no impairment) to 6 (higher impairment).

• Changes in Pressure Pain Thresholds [ Time Frame: Baseline, 48 hours, 96 hours, 1 week ]
  Changes in pressure pain thresholds will be determined with pressure algometry bilaterally over the leg and shoulder. PPT is defined as the exact time point where the pressure is first being perceived at painful.
• Changes in active knee extension test [ Time Frame: Baseline, 48 hours, 96 hours, 1 week ]
  Changes in range of motion (°; degrees) will be assessed in both sides using the active knee extension (AKE) test. AKE test: subject is lying prone with hip and knee flexed at 90°. Then, maximal knee extension is performed.
• Changes in knee-flexors maximal isometric muscle strength [ Time Frame: Baseline, 48 hours, 96 hours, 1 week ]
  Changes in knee-flexors maximal isometric strength (Newton) will be assessed by using a hand-held dynamometer.
• EMG measurement during the tests [ Time Frame: Baseline, 48 hours, 96 hours, 1 week ]
  Electromyography values will be taken from hamstrings during the performance of gait analysis and dynamometry
• Changes in thermography on hamstrings areas [ Time Frame: Baseline, 48 hours, 96 hours, 1 week ]
  A thermography image will be taken every day of assessment. Changes in colour pixeles will be analysed to determine temperature changes.
• Changes in static and dynamic baropodometry [ Time Frame: Baseline, 48 hours, 96 hours, 1 week ]
  Changes in static and dynamic baropodometry will be performed in every session by using a pressure platform.
• Changes in subjective perception of pain and impairment: Two questionnaire (Modified 7-item Likert Scales) [ Time Frame: 48 hours, 96 hours, 1 week ]
  Two questionnaire (Modified 7-item Likert Scales) are filled up by the subject to show subjective perception of pain related to movement along the recovery period

Basal measurements are taken in relation to the study variables. Immediately subjects perform eccentric exercise on right hamstrings to develop delayed onset muscle soreness (DOMS).

Measurements of the study variables are taken in the same conditions 48, 96 and 168 hours after the exercise to study the evolution of the variables while recovering from DOMS.

Basal measurements are taken in relation to the study variables.

The variables are:

• pressure pain thresholds
• electromyography values
• static and dynamic plantar pressure measurement
• active knee extensibility
• maximal strength of knee flexors
• thermography
• scales of pain perception

Immediately subjects perform eccentric exercise on right hamstrings to develop DOMS (delay onset muscle soreness).

Measurements of the study variables are taken in the same conditions 48, 96 and 168 hours after the exercise to study the evolution of the variables while recovering from DOMS.

Inclusion Criteria:

• not sedentary subject (IPAQ scale > 600 MET)
• healthy subjects, without pain nor injury at the moment

Exclusion Criteria:

• subjects with acute or chronic pain on every spot of pelvis or lower limbs at the momento or for the last 3 months;
• subjects with history of severe injury in the hamstrings muscles;
• presence of serious illness;
• presence of pathologies in relation to chronic pain (as fibromyalgia, migraine disorders, non specific and chronic lumbar pain);
• not commitment for continuity in the study program;