Endocrine Abstracts

Acromegaly, characterized by growth hormone excess, adversely affects the patients’ musculoskeletal and neural systems, consequently impairing physical function. Previous studies have noted walking impairments in patients with acromegaly (PWA). This study aimed to characterize the kinematic and kinetic changes during walking in PWA. Kinematics and kinetics of walking were evaluated in PWA (n=8) in biochemical remission and a control group of patients with non-functioning pituitary adenomas (PNA, n=8). The groups were of similar age, sex, and BMI and all participants underwent surgery to remove the pituitary adenoma. Self-reported survey data was used to compare joint pain, functional disability scores, and history of joint surgery between groups. PWA reported significantly higher back, hip, and knee pain and greater functional disability of the hip and knee than PNA. However, the history of joint surgery did not significantly differ between groups. Bipedal ground reaction forces and centre of pressure (COP) were measured using two AMTI force plates with one underneath each foot. Lower limb kinematics were measured using a 7-body segment model with anatomical 3D positions recorded using a 14-camera OptiTrack motion capture system. Force plate and motion capture systems were synchronized and sampled at 200 Hz. Lower limb kinematics and kinetics were calculated using Visual 3D. The outcome measures of the study consisted of walking speed, stride length, angular excursion, joint moments and joint power. Group differences were found in lower limb kinematics and kinetics during the stance phase. PWA exhibited increased hip and knee flexion, decreased hip adduction, and decreased ankle plantar flexion at push-off. Hip flexion moments were reduced, and hip abduction, knee extension, and knee abduction moments were elevated in PWA. There were no differences in ankle joint moments between groups. These kinematic and kinetic modifications during the initial stance phase resulted from a higher energy generation by hip extensors but lower energy absorption by hip abductors and knee extensors in PWA compared to PNA. In the midstance phase, PWA demonstrated lower energy absorption by hip flexors compared to PNA. Furthermore, PWA revealed lower energy generation by hip flexors, energy absorption by knee extensors, and energy generation by ankle plantar flexors during push-off. These results show that changes in the mechanics of walking in PWA are similar to those observed in patients with hip and knee osteoarthritis. However, some differences in the energy distribution pattern indicated a potential alteration in muscle activation strategies compared to patients with osteoarthritis.