Keep moving with kneecap pain

Keep moving with kneecap pain

Pain in the front of the knee, around the kneecap can be a common issue in people presenting to Physiotherapy. This issue can be caused by an irritation of the patellofemoral joint, the joint between your kneecap and the base of your thigh bone. Often pain can occur in this joint when running, walking up or down stairs or during other exercise such as squatting. Pain in this area often relates to pressure on the kneecap as it articulates with the bottom of your thigh bone – your femur. The force on this joint is mainly influenced by two things: the amount of force being produced by the quadriceps muscles on the top of your thigh, and the amount of knee bend or flexion that occurs when the joint is under load.

Here are a few strategies you could implement to reduce your patellofemoral pain whilst continuing to exercise:

1. Choose exercise activities that gradually expose the knee to greater stresses.

There is a systematic review by Hart et al. (2022) that has looked at the average reaction force that different activities place on the patellofemoral joint in healthy individuals.

Walking: 0.9x body weight

Descending stairs: 2.8x body weight

Ascending stairs: 3.8x body weight

Running: 5.2x body weight

Squatting: 1 – 18x body

Looking at these averages, a good way to try and reduce the load on the patellofemoral joint could be to target start with a low loading exercise such as walking and gradually progress to stairs and then running. As you can see, there is a very large variability in the loads that are placed on the knee during squatting movements. Therefore, if you can minimise the amount of knee bend during your squats, you may be able to reduce your knee pain.

2. Modify your current exercise program to reduce the stress on the knee joint.

We know that the joint reaction force will increase with greater knee bend. Choosing squat variations that limit your knee from bending more than 90 degrees could allow you to maintain lower body strength whilst reducing your pain. Choosing exercises that are double-legged rather than single-legged may reduce the tendency of your knee to track inwards, which may help to settle your patellofemoral pain.

If you are a runner, increasing your step rate may help you to settle your knee pain and keep you running. If you keep the same running pace, an increased step rate will reduce your stride length, which reduces the amount of knee bend through the weight-bearing portion of the running cycle. This can then reduce the reaction force in the patellofemoral joint, and it will be easier to maintain better alignment through your hips to avoid a scissoring pattern.

Then once symptoms have settled you can begin gradually re-expose the knee to more loads over time so that it can get used to it. As with many areas of the body, this advice is generalised and may not be affective for individuals with varied anatomy and movement patterns. Try a few of these strategies, and if you’re still having issues with your knee pain, we’d be happy to help you here at the clinic.

Reference:

Hart, H. F., Patterson, B. E., Crossley, K. M., Culvenor, A. G., Khan, M. C. M., King, M. G., & Sritharan, P. (2022). May the force be with you: understanding how patellofemoral joint reaction force compares across different activities and physical interventions—a systematic review and meta-analysis. British Journal of Sports Medicine, 56(9), 521–530. https://doi.org/10.1136/bjsports-2021-104686