WHAT IS THE COLLATERAL LIGAMENT (CL)?
The CL consist of 2 different fibers that run across both sides of the finger joints. These ligaments function to prevent shear forces, rotational forces and help stabilize the finger when bending and extending.
The image shows the 2 ligament that make up the collateral ligament of the finger:
1. Proper collateral ligament (PCL)
The PCL is tensioned when the finger is bent and relaxed when the finger fully straightens.
2. Accessory collateral ligament (ACL)
The ACL is tensioned when the finger fully straightens and relaxed when the finger is bent.
Mechanism of Injury
These structures passively restrain the joint by preventing excessive movement. They are able to elongate under stress to reach maximum stiffness, once the stress exceeds the ligament’s capacity to handle the load, strains will occur.
In the context of climbing, injury to the CL can occur when there are shear or rotational forces when holding on to pockets and crimps. Another way a climber may be exposed to these forces is when the finger is met with blunt trauma to the wall or a hold when performing big moves.
1. Shear force
2. Rotational force
3. Shear forces caused by blunt trauma
Signs & Symptoms
· Pain when trying to fully bend the finger (sometimes pain when the finger is fully straightened)
· Swelling on the affected finger, more prominent on the joint
· Pain when the finger is pushed to left or right
If you are experiencing any of the symptoms above, you may have and injured CL.
How to determine which CL is affected? There are simple self-tests to determine which ligament is affected.
In the picture above, the middle finger is used as an example to self-test for a CL injury.
The test is performed by applying shear forces onto the CL through pushing the finger to either the left or right. The test is positive if there is pain when pushing to either side of the finger. Pushing onto the middle finger from the left will load the left CL while pushing the middle finger from the right will load the right CL. The test can be performed when the finger is fully straightened or slightly bent to 30’ degrees.
Management
Early stage (0-7days post injury)
Goals: Protect affected finger to prevent further injury and manage pain and swelling.
Splinting the affected finger is a good way to prevent any shear forces to the affected joint. When wearing the splint, make sure the splint is not strapped on too tight.
Icing the finger to help manage excessive swelling and pain. Soaking the hands into cold water for 5 to 10 minutes 2x a day.
Most importantly REST! Taking a few days off climbing until swelling reduces is the best way to avoid any risk of re-injuring the joint.
Middle to Late stage (after 1 week)
Goals: Improve ROM and begin loading
1. Tendon gliding
2. Loading on CL
· Rubber bands are a good way to create measurable load onto the CL
· Always start off with lighter resistance and increase it over time (add more rubber bands)
· Use the pain level as a gauge for the intensity. Keep the pain level below 4/10, this will ensure that you do not over stress the ligament.
Written by Eugene Lee (Physiotherapist)
Reference:
1. Carruthers KH, Skie M, Jain M. Jam Injuries of the Finger: Diagnosis and Management of Injuries to the Interphalangeal Joints Across Multiple Sports and Levels of Experience. Sports Health. 2016 Sep;8(5):469-78. doi: 10.1177/1941738116658643. Epub 2016 Jul 15. PMID: 27421747; PMCID: PMC5010131.
2. Leong NL, Kator JL, Clemens TL, James A, Enamoto-Iwamoto M, Jiang J. Tendon and Ligament Healing and Current Approaches to Tendon and Ligament Regeneration. J Orthop Res. 2020 Jan;38(1):7-12. doi: 10.1002/jor.24475. Epub 2019 Sep 30. PMID: 31529731; PMCID: PMC7307866.