Training components crucial to optimize the training of arm/hand skill performance in subacute cervical spinal cord injury

Abstract

Individuals with cervical SCI identify arm–hand function as their highest priority for functional recovery. Improving arm–hand skilled performance is essential for performing meaningful activities and, in turn, supporting participation in daily life, which the World Health Organization defines as the ultimate goal of rehabilitation. In line with this perspective, this doctoral thesis focused on arm–hand rehabilitation aimed at improving arm–hand skilled performance, defined at the activity level of the International Classification of Functioning, Disability and Health (ICF), and the performance of meaningful activities. The overall aim was to investigate the essential training variables in arm–hand rehabilitation that support these outcomes in individuals with cervical SCI. Based on neurological and motor learning literature, three training variables were initially identified as central to arm–hand rehabilitation: motor training strategies, therapy dose, and motivation. These variables were systematically reviewed in the literature (Chapter 1). For motor training strategies, evidence showed that skill training alone, or combined with strength and endurance training, has a moderate effect on arm–hand skilled performance. Eight task-oriented training components were identified as important elements of arm–hand training: functional movements, a clear functional goal, real-life object manipulation, a context-specific environment, exercise variety, practice in multiple movement planes, total skill practice, and bimanual practice. With regard to therapy dose, the review yielded only one clear recommendation: training programs should last at least eight weeks. Other dimensions of therapy dose were poorly reported, limiting the translation of evidence into clinical practice. Motivation was rarely addressed in the reviewed studies, with only one program explicitly incorporating client-centered goals to enhance motivation. Overall, the available evidence was limited by the small number of studies focusing on individuals with cervical SCI. Building on these findings, therapists’ perspectives on the three training variables and key elements in arm-hand rehabilitation were explored through focus group discussions (Chapter 2). Therapists emphasized the importance of motivation as a crucial factor for engaging individuals with cervical SCI in arm–hand rehabilitation. While acknowledging the value of goal- and task-oriented skill training, they also highlighted the importance of strength, endurance, and analytical training as important training modalities to create optimal conditions for task-oriented practice. Regarding therapy dose, therapists stressed the need to tailor both session-level and program-level dose to the individual’s load capacity. Importantly, therapists expanded the initial set of variables by identifying additional factors necessary for improving skilled performance and supporting meaningful activities. These included knowledge of the person and their environment, explicit goal setting, and practice beyond formal therapy sessions to integrate the (re)learned meaningful activities in daily life. Understanding the individual and their environment was considered essential for applying a person- centered approach and adapting training variables to the individual. Goal setting was highlighted as a distinct and critical step in identifying personally meaningful activities that influence training and motivation. Therapists also emphasized that practice outside therapy sessions and after discharge is important for integrating relearned skills into daily life. The extent to which motor training strategies, therapy dose, and motivation were incorporated into current upper limb rehabilitation programs was explored in an observational study conducted over six months (Chapter 3). Analytical training was the most frequently used modality, accounting for 30.3% of training time, followed by skill training at 26.6%, primarily consisting of basic skill exercises, with complex skill training rarely applied. Only six task-oriented training components were incorporated in more than half of the sessions. Although planned daily therapy time ranged from three to three and a half hours, actual session duration was 78.3% of planned time, and active upper limb engagement constituted only 51.1% of the time allocated to upper limb training. Subjective therapy dose dimensions, including intensity and difficulty, were relatively low. Despite this, patient motivation remained high throughout rehabilitation. Notably, there was little to no change in training variables over the six-month period, indicating a discrepancy between current clinical practice, therapists’ priorities, and evidence-based recommendations. Given the limited guidance on therapy dose in the literature, therapists need to rely on their intuition to apply the correct therapy dose to the patients. Therefore, the accuracy of therapists’ estimations of active time, intensity, and difficulty was investigated (Chapter 4). The active time, intensity, and difficulty estimated by the therapist were compared to the patients’ estimations and objective measurements obtained from video recordings. The findings revealed that therapists systematically overestimated all three dimensions. Wrist-worn accelerometers provided a more accurate and unbiased measure of active upper limb time compared to the therapists’ estimations. These findings highlight a gap between the intended and delivered therapy dose, indicating opportunities to optimize training intensity and engagement within existing therapy hours. Although this thesis initially focused on three training variables, findings across qualitative and quantitative studies demonstrated that improving arm–hand skilled performance and daily activities requires a broader, integrated approach. The results from the systematic review, focus groups, and observational studies were synthesized into an evidence-based arm–hand rehabilitation framework (Chapter 5). A key contribution of this framework is the positioning of therapist-informed variables, knowledge of the person and environment, and goal setting, as the starting phases that guide all subsequent training decisions. This sequencing establishes a person-centered foundation, ensuring that motor training strategies and therapy dose dimensions are continuously adapted to the individual rather than applied in isolation. The framework also explicitly incorporates practice beyond formal therapy sessions as an essential step to support the transfer of skills into daily life and participation. The framework was refined through feedback from international experts and individuals with cervical SCI. Experts emphasized the need for more explicit assessment of personal and environmental factors, while refinements highlighted multiple ways in which integrating meaningful activities into daily life can enhance rehabilitation, including increasing therapy dose, promoting independence, and facilitating skill transfer. Individuals with cervical SCI confirmed the relevance of the framework and underscored the importance of early education, clear explanations of the purpose of training, and the fact that identifying meaningful goals is easier within the home environment. In conclusion, this thesis demonstrates that arm–hand rehabilitation in cervical SCI is a multidimensional and individualized process. While motor training strategies, therapy dose, and motivation are essential components, they must be embedded within a person-centered approach informed by knowledge of the person and their environment, explicit goal setting, and the integration of meaningful activities into daily life. Together, this supports the (re)acquisition and integration of meaningful activities into daily life, which directly contribute to participation, the ultimate goal of rehabilitation.