MotoPT: IMPROVE YOUR MOVE

Arm Pump Part II: The Passive Part of Arm Pump

Hello FTR Family, At the time of this writing, just after Thanksgiving, we are ramping up for Hare Scramble #3 by SADRA, always a fun and demanding Florida course. Of course, by the time you read this, it will be 2023 or very close to it. I hope you all had a great holiday season and are looking forward to the second half of this season as much as I am. Last month we spoke about what arm pump is; if you missed it, here is the synopsis. Arm pump is an exertional compartment syndrome. Exertional compartment syndrome of the forearm occurs when we use the muscles so much that all the blood goes into the forearm, and as the muscles swell, the blood has a hard time getting out. Eventually, the muscles and forearm tissues swell with blood to the point of putting pressure on our nerves and arteries. In our forearms, just like every other area of our body, our musculoskeletal system is divided into distinct compartments. The compartments are bracketed by rigid structures such as bones and fascia and contain all the body’s muscles, tendons, arteries, veins, nerves, and other soft tissues. Fascia is the dense, irregular connective tissue that offers structural support properties and often envelopes muscles as a sheath.

Fascia can be one of the critical tissues involved when people have arm pump that cannot be relieved with conservative measures. That being said, there are tools and techniques we use to make physical changes to the extensibility and rigidity of the fascia. At the very least, the goal is to improve the mobility of the fascia. My favorite technique is using my hands to actually bend the fascial compartment, which is a muscle play technique. Most of you instinctively do this when you get arm pump and grab and squeeze or massage your forearms.

Your forearm has two main muscle groups: the flexor group and the extensor group. The flexor group helps you flex your wrist and curl your fingers, as you grip your handlebars. The flexor side of your forearm is the side you see the most arm pump on since you are using those muscles the most. Here is a good stretch test that can become your first-line stretching exercise if you cannot fully complete the motion.

Put your arm straight out in front of you at shoulder height, palm up, and your elbow entirely straight. Extend your wrist toward the floor and extend your fingers straight down. Hopefully, you have the length of your forearm flexors for your fingers to point straight down to the floor, and your wrist is at approximately a 90-degree angle to your forearm. If your wrist is not perpendicular to the floor and your fingers are not pointed straight down, you likely have decreased muscle length of a forearm flexor.

Next, gently grab the pads of your fingers with your other hand, all four of them, and pull your fingers back towards you, so they are straight down or even past vertical. What do you feel? If you feel a strong stretch on the palm side of your forearm, you now know how to perform the general stretch for all forearm flexors. Make sure your elbow stays fully straight during the movement. To improve the length of these muscles, hold the stretch in a strong but

comfortable position for 5 minutes, once per day, at minimum. This will gradually add length to your forearm flexors. In the future, once you can actively get wrist perpendicular to the floor and your fingers pointed straight down without pulling them back with your other hand, you no longer need this stretch. If you get arm pump worse on one side, compare both sides as you may notice a significant difference between the right and left forearm, which is another indication to perform this stretch. If you did not get the stretch feeling in your forearm or you had pain with the motion, do not perform the stretch. lead to exertional compartment syndrome, i.e., arm pump. When you get the correct length of the tight muscles, the force required to grip the bars decreases, and so does your arm pump and forearm pain (Lewit et al., 2015). A qualified healthcare professional, such as a physical therapist, can perform length tests of the specific muscles in the forearm to determine which particular muscles are tight and need to be stretched to maximize the effectiveness of this treatment strategy to decrease arm pump. Decreased muscle length must be addressed to decrease the passive insufficiency of your forearm.

Why is it so important to have the full length of our forearm flexors? Because if they are tight it creates the phenomenon of passive insufficiency. Passive insufficiently is when the length of a muscle limits the amount of simultaneous movement at two or more joints (Shapiro & Kamel, 2020). Since your forearm flexors cross multiple joints, including your elbow, wrist and fingers, if they are tight they can limit your ability to flex your fingers i.e., grip your handlebars if your elbow position changes such as charging through a set of whoops or hitting an unexpected root. This causes the other muscles in the forearm to work harder to overcome this limitation in range of motion. As muscles work harder the amount of blood they need increases, which can Even if you have been struggling with arm pump for years, visit me at the races; you might be surprised how much I can improve your arm pump or even alleviate it completely. Before you start any new exercise program, I highly recommend you consult a physical therapist or physician for a general health and physical activity readiness screening. If you are experiencing pain while riding, it is always beneficial to have a complete evaluation by a physical therapist or physician. If you have any questions or comments, please email me at contact@motopt.com, or call me at 904-395-5379. Let’s IMPROVE YOUR MOVE so you can ride pain-free with MotoPT. Matthew Daugherty PT, DPT, OTR/L, MOT, DBA Associate Professor Board-Certified Orthopaedic Clinical Specialist Fellow, American Academy of Orthopaedic Manual Physical Therapists Manual Therapy Certified Intramuscular Dry Needling Certified

References

Lewit, K., Čihák, R., & Lepšíková, M. (2015). Insufficiency of finger flexors and extensors and its importance for hand function: A clinical and electromyographic investigation. International Musculoskeletal Medicine, 37(4), 178–183. https://doi.org/10.1179 /1753614615Z.000000000116

Shapiro, J., & Kamel, B. (2020). Passive Muscular Insufficiency: The Etiology of Gastrocnemius Equinus. Clinics in Podiatric Medicine and Surgery, 37(1), 61–69. http://10.0.3.248/j. cpm.2019.08.006