Motor training is a widely used therapy in many pain conditions. The brain's capacity to undergo functional and structural changes i.e., neuroplasticity is fundamental to training-induced motor improvement and can be assessed by transcranial magnetic stimulation (TMS). The aim was to investigate the impact of pain on training-induced motor performance and neuroplasticity assessed by TMS. The review was carried out in accordance with the PRISMA-guidelines and a Prospero protocol (CRD42020168487). An electronic search in PubMed, Web of Science and Cochrane until December 13, 2019, identified studies focused on training-induced neuroplasticity in the presence of experimentally-induced pain, 'acute pain' or in a chronic pain condition, 'chronic pain'. Included studies were assessed by two authors for methodological quality using the TMS Quality checklist, and for risk of bias using the Newcastle-Ottawa Scale. The literature search identified 231 studies. After removal of 71 duplicates, 160 abstracts were screened, and 24 articles were reviewed in full text. Of these, 17 studies on acute pain (n = 7) or chronic pain (n = 10), including a total of 258 patients with different pain conditions and 248 healthy participants met the inclusion criteria. The most common types of motor training were different finger tasks (n = 6). Motor training was associated with motor cortex functional neuroplasticity and six of seven acute pain studies and five of ten chronic pain studies showed that, compared to controls, pain can impede such trainings-induced neuroplasticity. These findings may have implications for motor learning and performance and with putative impact on rehabilitative procedures such as physiotherapy.

While muscle overload is commonly implicated in musculoskeletal pain conditions, real-time assessment of associated behavioural and physiological features is challenging. This study aims to investigate the relationship between self-reported awake bruxism using Ecological Momentary Assessment (EMA) and jaw muscle activity registered by surface electromyography (sEMG), and differences between individuals with and without temporomandibular disorder (TMD) pain. Seventy participants (38 women, 32 men), of which 31% reported pain, completed 3-day EMA using a smartphone application combined with a sEMG device only for day 1. Overload, defined as muscle activity exceeding 20% of maximum voluntary contraction (MVC), was evaluated for duration and area under curve (AUC). A strong correlation was observed between EMA-reported bruxism and sEMG overload duration (ρ = 0.62, p < 0.001). AUC showed a correlation with EMA only in the TMD group. Participants with TMD pain exhibited shorter high-intensity bursts (60-79% MVC, p ≤ 0.005) but prolonged low-intensity muscle activity (20-39% MVC, p < 0.001). Bruxism behaviour and stress levels were higher in women and in individuals with pain. The results suggest that combining EMA and sEMG provides valid assessment of musculoskeletal overload, capturing both perceptual and physiological dimensions. Incorporating EMA in pain management can identify pain-related risk behaviours, thus supporting tailored patient-centred interventions.