Relationships between quadriceps muscle strength, balance and proprioception of the knee joint with disease severity and exercise capacity in patients with chronic obstructive pulmonary disease (COPD).

While studies on the exercise capacity and quadriceps muscle strength in COPD patients are ongoing, no sufficient studies regarding of proprioception and balance are available. We aimed to investigate the relationship disease severity and exercise capacity by studying proprioception of the knee joint and balance beside the knee extensor and flexor muscle strength and by comparing the control group. The disease severity of COPD patients was classified according to GOLD (Global Inıtiative for Obstructive Lung Diseases) 2017 criteria. The study was conducted on 20 healthy individuals and 82 patients between forty and eighty years old. The exercise capacity of the participants was measured with 6-minute walk test, muscle strength and knee joint proprioception with isokinetic dynamometer, and postural stability with Biodex Balance System. Their results were compared and evaluated with the SPSS version 21 statistically. In our patients, exercise capacity with muscle strength were reduced significantly in parallel with disease severity compared to healthy individuals (p<0,001, p<0,05, respectively). A positive correlation between them was discovered. Muscle weakness and low exercise capacity of our patients demonstrate compatibility with literature. We may state that age, gender and methodic differences are influential on finding loss in proprioceptive sense of the knee joint in our patients. We suggest that this result is alternative to loss of proprioceptive sense in thoracal muscles and that it ensured the continuity of the static and dynamic postural control. In conclusion, we recommend that COPD patients are to be directed to pulmonary rehabilitation programs from the earlier period in order to increase life quality of them.