The objects of this research are to investigate the ability of the motor learning and test the possible differences between younger and older healthy human, and between non-pain and acute experimental pain and chronic clinical pain conditions.

The project consists of four experimental studies. In the first experiment, younger and older healthy human subjects are involved in a short-term neuromuscular training on the accuracy and precision of knee movement to investigate the possible age effect of the motor learning. The second experiment focuses on the experimental pain on the learning effect of the younger subjects. The third experiment will investigate a group of knee osteoarthritis patients to show the influence of chronic pain on the motor training compared with age-, gender-matched pain free subjects. 3D camera tracking system will be used to record the knee movements at the baseline and after 6-day motor task training. The variability in amplitude of the values of knee movements was transformed to percentage in relation to the target position (accuracy) or to the mean position (precision). The results of the study will contribute to both basic and clinical understanding of the mechanisms related to knee movement control and influences of varies painful conditions.

Inclusion Criteria:

• • Aged 18-30 or 50-65 years

  • Free from ongoing or chronic pain
  • Right dominant leg
  • Speak and understand English
  • Aged 50-65 years.
  • Diagnosed with knee OA (according to American College of Rheumatology classification) with pain in left or both knees for more than six months
  • Have ongoing pain rated above 2 on a 0-10 Visual Analogues Scale (VAS) in the previous week.
  • Right dominant leg
  • Speak and understand English
  • Aged 50-65 years
  • Diagnosed with knee OA
  • Have had total knee arthroplasty on left or both knees
  • Right dominant leg
  • Speak and understand English

Exclusion Criteria:

• • Pregnancy or intent to become pregnant, breast feeding

  • Regular use of analgesics, including simple analgesia and NSAIDs
  • Frequent recreational drug or alcohol use
  • History of knee joint pathology or injury
  • Previous neurologic, musculoskeletal or mental illnesses
  • Practicing sport activities on a regular basis
  • Lack of ability to cooperate
  • Regular use of analgesics, including analgesia and NSAIDs for the last 24 hours
  • Frequent recreational drug or alcohol use
  • Previous neurologic, musculoskeletal or mental illnesses
  • Practicing sports activities on a regular basis
  • Lack of ability to cooperate
  • Regular use of analgesics, including analgesia and NSAIDs for the last 24 hours
  • Frequent recreational drug or alcohol use
  • Other disorders or injuries in the knee joints
  • Previous neurologic, musculoskeletal or mental illnesses
  • Practicing sports activities on a regular basis
  • Lack of ability to cooperate