Pump Arm

Pump arm is a very common and debilitating condition that affects a variety of athletes. The commonest sports that are affected motorcycle racing and rowing.

Pump arm is also known as chronic exertional forearm compartment syndrome.

The forearm muscles are contained within a fibrous bag in the forearm. With activities that require forced prolonged gripping the pressure builds up inside the fibrous bag in the forearm. This causes pain, pins and needles in the hand and inability to continue to grip. The forearms often feeling very hard and tense during the activity. The condition commonly affects both the front (volar – flexor) and back ( dorsal – extensor) aspects of the forearms. The back of the forearm can be affected especially on hard braking circuits.

The diagnosis of pump arm is usually made from a strong positive story as above but the clinical examination is often normal. Other causes of forearm discomfort and pins and needles need excluding with a face-to-face examination prior to any potential surgical intervention.

There are a number of investigations that can be performed for pump arm that include measuring the intra-muscular pressures measurements with a canula or MRI scans pre and post exercise.

In my experience the pressures that are generated when competing cannot be replicated in the clinical environment with pressure measurements nor pre-and post MRI scans.

I therefore generally rely on the clinical history and exclusion of other potential diagnoses.

Pump arm is so common that the majority of athletes have discussed their condition with colleagues and other competitors with very similar symptoms that have resolved with pump arm surgery.

A zoom consultation can often be performed to discuss the condition or preferably a face to face consultation with a clinical examination. If a zoom consultation is performed for logistical reasons and surgery decided, then the athlete will be formally examined on the day of surgery to exclude other possible diagnoses.

Non operative measures include physical therapy, taping , acupuncture and tiger balm patches. If these do not help surgery may be considered.

The surgery is performed as a day case procedure. The type of anaesthetic depends on if both arms or just one arm is being released.

My personal preference when treating one arm is to release the fibrous bag on both the flexor (volar) and extensor (dorsal) aspects of the forearm. This is by 2 separate incisions that are both approximately 10-15 cms long. This procedure can also be performed endoscopically through much smaller skin incisions but the incision in the fascia remains the same length over the underlying muscles.

If one arm is being released (2 incisions) then the procedure can be performed under local anaesthetic without a tourniquet. This is on account of the fact that I mix the local anaesthetic with adrenaline which reduces bleeding allowing for tourniquet free surgery.

If however both arms are being released (4 incisions) then the procedure can only be performed under general anaesthesia due to the volume and dose of local anaesthetic that would be required becoming potentially too high.

The surgery is relatively straightforward and involves making a skin incision and carefully protecting the underlying cutaneous sensory nerves. The fibrous bag is identified and incised longitudinally along its length. Very occasionally, and particularly on the extensor side, there are separate fibrous septae that run longitudinally and the fascia needs releasing either side of the septae.

I close the wound with a subcuticular buried suture that does not need removal. I cover the wounds with steristrips ( butterfly strips) apply a dressing and large bandage. The hand and elbow are not included in the bandage.

The bandages can be removed after a few days but the wound needs to be kept covered until heel at 10 to 14 days.

I recommend a firm tubigrip for the first 4 weeks to reduce the risk of a seroma formation which is a buildup of fluid under the skin.

Return to racing varies between athletes. The first principle is always to ensure that the athlete is safe to ride and is no danger to themselves or other riders. There is always a risk of opening up the wound within the first few weeks in the event of an accident. I generally advise return to racing after 2 to 4 weeks if pain-free, able to grip fully and ride safely.

There are complications associated with the surgery and these include a failure to resolve the symptoms (if there is an alternative diagnosis), infection, weakness, hernia formation, seroma, injury to vessels and nerves causing bleeding numbness or a painful nerve ending called a neuroma. There is a very small risk of chronic regional pain syndrome (CPRS). Whilst the initial scar is a narrow faint line this can stretch in some individuals and very rarely become bumpy and unsightly. Pump arm can recur after several years and may need repeating.

Generally athletes are very pleased with the results of pump arm surgery.

Watch a short video of the operation performed wide awake (viewer beware).