The Kinematic Chain: A Multifactored Approach to Joint Pain

Movement is Complex

By: Dr. Jeremy Bate, PT, DPT

I have encountered many different musculoskeletal conditions in my time as a physical therapist. I’ve treated pain in nearly every joint in the body due to chronic issues, injuries, post-surgical recovery, neurological conditions, nerve pain - the list goes on. However, in my experience, people almost always have a common problem: pain in one joint causing pain in another. 

What exactly causes this? There is a famous phrase in physical therapy that is both beloved by clinicians and frustratingly vague: “It depends…” 

Physical therapists are experts in movement and function. That being said, a good portion of our education and approach to recovery hinges not only on knowledge of the body, but how it is most efficiently used to accomplish everyday movements. These can range from rolling over to snooze your alarm to doing a clean & jerk for your next powerlift. No matter how simple or complex a task may seem, there are almost always multiple muscles and joints at work to get it done.

What is the Kinematic Chain?

This is where the concept of the Kinematic Chain comes into play. Your joints never work in isolation. Each movement is like a symphony of structures all working together to create a seamless motion. To put it simply, the idea of the Kinematic Chain is how movements of one joint work in tandem with others. Let’s look at something as deceptively simple as opening a water bottle. 

Unscrewing the cap to a bottle involves: the many joints of your fingers, hand, and wrist. Coordinating those movements with the twisting and bending of your elbow. Lifting and rotating your shoulder. Timing all of this with all of the muscles that control these joints, calibrating the force needed to not crush the bottle, holding the bottle with your other hand… and all of this before you’ve even taken a sip. 

Luckily for us, we don’t have to consciously think of all of these factors at once. But, when one of these factors is out of whack, it is noticeable immediately. Imagine listening to an orchestra playing a song, but the trumpets are playing the wrong notes - even if you don’t know the song, you’d hear that something is wrong. Physical therapists are like the conductor who can help guide the band back into harmony. 

Where Does Pain Come In?

If a muscle or joint in the Kinematic Chain fails, then it can force the other parts to “pick up the slack” to accomplish each motion. This is how dysfunction in one area, for example the knee, could start to cause pain/limitations in another joint such as the neighboring ankle or hip. Similarly, dysfunctions of the ankle/hip can exacerbate issues in the already painful knee.

This extra strain often results in increased pain. At its simplest function, pain is just your body’s way of telling you that something is wrong; it’s like hearing those trumpets play the wrong notes. 

So What Do We Do?

In terms of how physical therapy can help, much of it comes down to careful evaluation so that we can target the root of the issue. If we want the orchestra to play well together, we can’t just focus on the trumpets. We need to make sure everyone is on the same page meaning we have to make sure that the saxophones are doing what they’re supposed to, the violins are in tune, and - well, I’m sure you understand by now. 

Movement analysis is always the key to teasing out these issues. Many times, dysfunction of multiple joints feed into each other. This can amplify problematic movement patterns and exacerbate pain. 

Conducting the Orchestra

I have worked with a patient before who would get episodes of worsening pain in her left knee. Some days when I’d see her, she would be limping and barely able to navigate stairs. Now, upon first glance, many of her symptoms point to the left knee being the problem. Pain in the left knee joint, the left thigh muscles, her left calf, and a walking pattern that keeps weight-bearing on the left leg to a minimum. 

However, the combination of two things prompted me to dig deeper:

1. The episodic nature of her left knee flare-ups and her usual exercises having diminished effectiveness

2. Knowing her personal factors such as her job demands, her role as a loving grandmother to two grandsons, and a fairly sedentary lifestyle. 

I was not convinced that the problem was only in that left knee.

Looking very closely at her walking pattern including the way her feet make contact with the ground and the way her hips bring her legs forward, I felt I was going in the right direction. After testing the movement of her pelvis and making sure that there were no recent events that may cause the increased knee pain, I deduced that her right hip caused the recent left knee flare up. 

You may ask: What? The right hip? How? The answer was simply that her right hip muscles were stiff. While walking, she took smaller steps on the right leg compared to the left. On the stairs, her left knee was doing the heavy lifting because her right hip had decreased range of motion. This limitation of the right hip resulted in various compensations that put increased stress on the left leg. She did not even notice that there was anything wrong in the right hip. 

What Did I Do?

I continued to work on her left knee, but added much more mobility work for her right hip including various stretches, targeted range of motion exercises, and I performed hands-on joint mobilizations to free up the movement in the pelvis. After about 3 sessions like this, open communication about her symptoms, and diligent use of her home exercises, she was able to walk with significantly decreased left knee pain (going from 8/10 pain to 3/10 pain) and for longer periods of time (up to 20 minutes from 5 minutes). She was also finally able to use the stairs again comfortably. Working on her movement patterns and making sure everything was in-sync again was the missing piece that allowed her to start making progress again.

In Summary

Fortunately, I know that patient very well. She is my mother after all. The kinematic chain isn’t the only thing that helped me figure out how to help her. Knowing the way she needs to move on a daily basis and what kind of motions she wants to do are crucial in putting that puzzle together. 

However, I make it a point to bring this level of detail and care to everyone I treat. The reason I chose physical therapy as a career is to help people like my mom not just feel better, but get back to doing what they want to do. I am always acutely aware that the person I’m treating is somebody’s parent, sibling, spouse, and a person that wants to live their best life. 

It is incredibly frustrating to hit that wall and feel like nothing is working when you’re putting in so much effort to improve. Sometimes it just takes a shift in perspective and a careful look at the smaller details to help break past that plateau.