This trial is part of the spastiCRYO clinical research project. The primary objective of this clinical trial is to test the hypothesis: Upper limb nerve cryoneurolysis is non inferior to the usual care and has therapeutic add value in dealing with shoulder pain and functional problems caused by spasticity and motor impairment. It is a non-inferiority study on the referred topic, comparing the therapeutic effect (improvement in function and pain) of cryoneurolysis of selected nerves (lateral pectoral nerve and thoracodorsal nerve) with the usual care: intramuscular botulinum neurotoxin type A (BoNT-A) injection of pectoralis major, teres major and subscapularis muscles. The hypothesis is that cryoneurolysis is not inferior to the usual care in terms of magnitude of the therapeutic effect and might have a therapeutic add-value in terms of duration of that effect. Two secondary hypotheses are firstly, that cryoneurolysis is a safe procedure that can be deployed in a rehabilitation hospital setting with minimum requirements to perform mini-invasive procedures and secondly that selecting patients who might benefit from this treatment is straightforward. To test these hypotheses, the research team will gather, analyse and compare outcome measures data from the endpoints which are the changes along the trial duration in shoulder pain, upper limb function, involved muscles spasticity, shoulder range of motion (abduction and external rotation) level of impairment, and follow-up of potential adverse effects in two independent and equivalent groups of participants who have shoulder pain and functional limitations caused by spasticity and are in a stable phase of their condition. Participants in one group (cryoneurolysis arm) have one session of selected nerves ultrasound and neurostimulation guided cryoneurolysis and participants in the other group (BoNT-A arm) have one session of ultrasound and neurostimulation guided injection of BoNT-A in the pectoralis major, teres major and subscapularis. The participants of the two groups follow an upper limb analogous rehabilitation program for 24 weeks after each intervention. Longitudinal follow-up in the trial will take 24 weeks. In a real-world scenario, within 24 weeks the effect of Bont-A intramuscular injection has already waned, and the procedure should be repeated. Secondary objectives are to compare changes in upper limb sensory function and electroneuromyographic parameters with the intention to understand the cryoneurolysis mechanism of action and the reversibility of this mini-invasive intervention. Changes in quality-of-life dimension of participants is a secondary endpoint as well.