Highlights What are the main findings? Individuals with COPD and sarcopenia exhibit poorer balance performance and reduced activation of lower limb muscles compared to those without sarcopenia. What is the implication of the main finding? It is crucial to implement prevention and management strategies that include strengthening exercises for patients with COPD and sarcopenia to reduce the risk of falls. There is a need for more detailed assessments and specific rehabilitation programs to improve balance and muscle strength in patients with COPD and sarcopenia.Highlights What are the main findings? Individuals with COPD and sarcopenia exhibit poorer balance performance and reduced activation of lower limb muscles compared to those without sarcopenia. What is the implication of the main finding? It is crucial to implement prevention and management strategies that include strengthening exercises for patients with COPD and sarcopenia to reduce the risk of falls. There is a need for more detailed assessments and specific rehabilitation programs to improve balance and muscle strength in patients with COPD and sarcopenia.Abstract Aim: The aim of this study was to compare balance performance and electromyographic activity in individuals with COPD, with and without sarcopenia. Method: Thirty-five patients with COPD were classified with and without sarcopenia according to EWGSOP criteria. Balance was assessed using a force platform under four conditions: standing with feet apart and eyes opened (FHEO), eyes closed (FHEC), on an unstable surface (US), and on one leg (OLS). The surface electromyography activity of lower limb muscles and trunks was recorded. Additionally, the timed up and go test (TUG) and the Brief Balance Evaluation Systems Test (Brief-BESTest) were also utilized. Results: Under the FHEO, FHEC, and US conditions, individuals with sarcopenia demonstrated increased velocities, larger oscillation amplitudes, and greater center of pressure displacements under the US condition (p <= 0.02). They also showed a higher activation of the scalene, sternocleidomastoid, and abdominal muscles during OLS, along with a reduced activation of the tibialis anterior during OLS and US, and a decreased activation of the vastus medialis during FHEC and US (p <= 0.04). Furthermore, sarcopenic COPD patients exhibited poorer performance on the TUG and Brief-BESTest compared to their non-sarcopenic counterparts (p <= 0.02). Conclusions: Individuals with COPD and sarcopenia demonstrated greater instability in both bipedal stances and on unstable surfaces, as well as poorer performance in both dynamic and static balance assessments. Furthermore, these individuals exhibited reduced muscular activation in the lower limbs compared to those without sarcopenia.