Patients with congenital or acquired upper limb structural abnormalities and peripheral nerve or brachial plexus palsies have significant loss of function. The use of orthoses may improve function particularly in performing specific tasks for which the orthoses are designed, depending on the patients' deficiencies and needs. The performance of orthoses may be enhanced by being light-weight, motor-driven, and ergonomic.

This pilot, prospective study is designed to test the feasibility and effectiveness of the specially designed orthoses.

Inclusion Criteria:

• Patients with any congenital or acquired upper limb structural abnormalities
• Patients' condition is not suitable for surgical intervention or patients are not keen for surgical treatment

Exclusion Criteria:

• Patients have no available muscle signal input
• Patients fitted with a pacemaker or an implantable cardioverter defibrillator (ICD) or other implantable electrical devices
• Patients with contact dermatitis