People with mild Parkinson's disease have impaired force production in upper limb muscles: A cross‐sectional study

Abstract

Background There has been little examination of force production of the upper limb in people with Parkinson's disease (PD), despite its impact on activities of daily living and clear evidence that force production is significantly reduced in lower limb muscle groups. The aim of this study was to determine the force production of the major muscle groups of the upper limb in people with PD during the “on” phase after medication, compared with aged‐matched neurologically‐normal controls. Method A cross‐sectional study was carried out. Participants Thirty people with mild PD (Hoehn Yahr mean 1.1) and 24 age‐matched neurologically‐normal controls. Outcome measures Maximum isometric force production of the shoulder flexors, extensors, abductors, adductors, internal rotators and external rotators, elbow flexors and extensors, wrist flexors and extensors and hand grip using dynamometry. Results There was a significant impairment in force production in all upper limb muscle groups, compared with control participants, except in the wrist flexors. On average the deficit in force production was 22%, despite people with PD having mild disease, being physically active and being measured during the “on” phase of medication. The most severely affected muscle groups were the upper limb extensors. Conclusion People with PD have a significant deficit in force production of the upper limb muscle groups compared with age‐matched neurologically normal controls. Clinical Implications Regular assessment of strength of the upper limb should be considered by clinicians and strengthening interventions could be implemented if a deficit is identified.

Research hotspots and trends of transcranial magnetic stimulation in Parkinson’s disease: a bibliometric analysis

“…Studies have been conservatively estimating that the number of people with PD will increase from 6.9 million in 2015 to 14.2 million in 2040 ( Pringsheim et al, 2014 ; Dorsey et al, 2018 ). Clinical symptoms of PD are mainly resting tremor, physical dyskinesia, postural instability, gait difficulty and rigidity ( Jankovic, 2008 ; Salmon et al, 2023 ; Scully et al, 2023 ). However, the pathogenesis of PD is still unclear, and the mainstream view is that PD is caused by a combination of genetic, environmental and aging factors that may lead to degeneration and apoptosis of dopaminergic neurons in the substantia nigra ( Puschmann, 2017 ; Zhang et al, 2018 ; Marras et al, 2019 ).…”