Physical Activity, Knee Joint Loading and Joint Health

Lead researcher and their location/institution

Karl Morgan, University of Bath

Who can get involved

You can participate if:

  • You are 18-39 years old.
  • You have had an ACL injury and surgical reconstruction between one and seven years ago.
  • You have completed your ACL reconstruction rehabilitation and either a doctor or physiotherapist has cleared you to participate in physical activity.
  • You sustained damage to either your meniscus or cartilage, or sustained bone bruising when you injured your anterior cruciate ligament.

You can participate regardless of the type of reconstruction surgery you had.

Type of study:

Cross-sectional and observational


Within a two-hour commute of Bath.

About the project

Hundreds of thousands of anterior cruciate ligament reconstruction procedures are undertaken annually worldwide. Alarmingly, approximately 50% of people are diagnosed with a disease called post-traumatic osteoarthritis (PTOA) 10-17 years after the surgery. One thing that may increase the chances of getting PTOA after surgery is being physically inactive; however, little research has investigated the relationship between physical activity and indicators of joint health following injury.

Consequently, our primary aim to investigate the relationship between physical activity and systemic (found in urine and blood) biomarkers of cartilage synthesis and breakdown.

What is involved?

To investigate these associations, we will ask participants to attend the laboratory on two occasions, spaced eleven days apart.

  • At the first laboratory session, we ask participants to provide blood and urine samples, undergo whole body and leg medical imaging, complete questionnaires relating to their joint health, and undertake a sub-maximal oxygen uptake assessment whilst running.
  • Between laboratory visits, we ask participants to wear devices that measure physical activity for ten days.
  • At the second laboratory session, we ask participants to provide blood samples and to run on a treadmill which measures the force of each step taken, whilst wearing reflective markers, an accelerometer, and electromyography devices for 30 minutes at a vigorous intensity.
  • We also ask participants to attend a third laboratory session to provide another blood sample 24 hours after the run.

Find out more

If you have any questions or are interested in taking part in the study, then please get in touch with the lead researcher (Karl Morgan,, +44 (0)1225 38 6399).