The goal of this clinical trial is to learn the effects of robot-assisted therapy using the ArmeoSpring on upper limb function compared to conventional occupational therpay in individuals with cervical spinal cord injury (cSCI). The main questions it aims to answer are:

- Which of the two forms of therapy, robot-assisted therapy or conventional occupational therapy, is more effective in terms of improving arm and hand function?

The study is designed as a cross-over trial, which means that each participant will receive both therapy forms consecutively, whereas the order is assigned randomly (either robot-assisted therapy first and then occupational therapy, or vice versa).

In addition to their clinical routine therapy , participants will:

• complete a baseline assessment
• practice one therapy form (either robot-assisted or occupational therapy) with one arm for 6 weeks (3 x 30 min per week)
• complete a intermediate assessment
• practice the other therapy form (either occupational or robot-assisted therapy) with one arm for 6 weeks (3 x 30 min per week)
• complete a post assessment
• complete a follow-up assessment (if the post assessment was completed prior to 150 days post-injury)

After cervical spinal cord injury (cSCI), motor and sensory impairments cause limitations in upper limb function which affect performance of activities of daily living (ADLs), independence and, ultimately, restrict participation and quality of life. Previous studies have shown that individuals with tetraplegia consider improvements in upper limb function to be one of the most significant factors in improving their quality of life. Small improvements in upper extremity function through rehabilitation can lead to substantial increases in independence with ADLs, quality of life and community integration. Repetitive and activity-based exercise can facilitate recovery after SCI by inducing practice-dependent brain and spinal plasticity. To achieve high numbers of repetitions, specialised rehabilitation centres apply innovative therapy methods like robot-assisted therapy (RT) aiming to improve upper limb function. Integrating robotic devices into daily clinical practice may save personnel resources while enabling high-intensive and individualised therapy using motivating feedback (e.g., gamification) and allowing for close monitoring of therapy sessions. Evidence suggests that robot-assisted interventions are safe, feasible and can reduce active assistance provided by therapists.

However, the clinical effectiveness of robot-assisted interventions for patients after cSCI has not been proven so far. For the devices used at the Swiss Paraplegic Centre (SPC) for upper extremity therapy after cSCI, there are only two studies to date that have followed a randomised controlled trial (RCT) design, and both were conducted with inadequate methodological quality (e.g. recruitment period one or two years post-injury respectively). This introduces a lot of variance and it thus remains open whether RT and conventional occupational therapy (OT) just have similar effects, or whether potential effects have been blurred due to imprecise study designs. Moreover, while both RCTs used the actively supporting ArmeoPower, internal analyses have shown that the passively supporting ArmeoSpring is the by far mostly used robotic device for training of the upper extremity inhouse. The ArmeoSpring is an instrumented arm orthosis with a spring mechanism (no actuators) for adjustable antigravity weight support for the arm in a large 3D workspace. However, neither of these robotic devices has ever been properly evaluated for clinical effectiveness .

Therefore, the aim of this study is to systematically investigate the effects of robot-assisted therapy (using the ArmeoSpring) on upper limb function compared to conventional occupational therapy in individuals with intermediate (between 2 weeks and 6 months after injury) cSCI.

Inclusion Criteria:

• Informed Consent signed by the subject
• Intermediate (>16 days and ≤81 days post-injury) traumatic or non-traumatic cSCI during primary rehabilitation at the Swiss Paraplegic Centre (SPC)
• Neurological level of injury: C1-T1
• American Spinal Injury Association Impairment Scale (AIS): A-D
• Impairment of upper limb function (GRASSP-QtG score unilateral < 25 at baseline t0)
• Ability to sit for 60 minutes and perform training with ArmeoSpring
• Stratification parameters available

Exclusion Criteria:

• Inability to follow the procedures of the investigation
• Severe concomitant neurological disease
• Concomitant neurodegenerative or progressive diseases
• Impairment of upper limb function due to peripheral nerve lesions
• Severe concurrent medical disease or any other issue that in the opinion of the investigator would confound the results
• Orthopedic limitations of the upper limb
• Device specific contraindications
• Participation in other interventional trials

All IPD that underlie results in a publication.