Introduction and objective:
Guyon canal syndrome (GCS) is rare neuropathy of the ulnar nerve, caused by its compression at the level of the wrist. In GCS, nerve compression may be caused by endogenic and exogenous reasons. It leads to motor or sensory disfunction regarding IV and V finger and hypothenar area. When symptoms ocurr among cyclists, the conditio is described as handlebar palsy – malfunction due to long-distance bike rides, as a result of repeatable vibrations and bearing bodyweight on wrists and hands.

Review methods:
The Sumary is based on academic literature and scientific publications available in Portal Komunikacji Naukowej, PubMed and NCBI – National Library of Medicine databases. After evaluation of abstracts, articles were selected and analyzed, considering the references citated. Publications that were analyzed, was two academic literature positions in Polish and both Polish and international publications from the fields of neurology, orthopaedics and radiology, containing a prospective study, retrospective study, systematic review, case study and several articles.

Abbreviated description of the state of knowledge:
Diagnostic methods of GCS were based on the evaluation of clinical symptoms and radiological or electrophysiological methods, such as USG, MRI or EMG. Treatment is based mainly on conservative management – rest, NSAIDs and steroid injections. Cyclists should take into consideration change of gear or bike position. The ultimate methods are surgical treatments, based on relieving compression of the ulnar nerve.

Summary:
Guyon canal syndrome is a significantly rare condition, often connected with sport activities, leading to malfunction of the hand mainly in its hypothenar area, which can be treated conservatively and surgically.