The goal of this clinical trial is to evaluate whether dry needling combined with therapeutic exercise improves shoulder proprioception in amateur athletes with subacromial pain syndrome. The study will also assess its effects on dynamic stability, strength, pain, and functional disability.

The main questions this study aims to answer are:

Does dry needling improve shoulder proprioception compared with therapeutic exercise alone? Does dry needling improve dynamic shoulder stability and muscle strength? Does dry needling reduce pain and upper limb disability?

Researchers will compare a group receiving dry needling plus therapeutic exercise with a group performing therapeutic exercise alone to determine whether the combined intervention produces better outcomes.

Participants will:

Be randomly assigned to one of the two treatment groups. Perform a home-based therapeutic exercise program for 3 weeks. Complete assessments of proprioception, dynamic stability, strength, pain, and functional disability before and after the intervention.

Subacromial pain syndrome (SAPS) is one of the most common causes of shoulder pain and dysfunction in both the general population and athletes involved in repetitive upper-limb activities. In sports requiring overhead movements, throwing actions, or repetitive shoulder loading, the increased mechanical demand placed on the glenohumeral joint may contribute to functional impairments, persistent pain, and reduced athletic performance.

Several studies have reported proprioceptive deficits and sensorimotor control alterations in individuals with SAPS. These impairments may affect joint position sense, muscular coordination, and dynamic shoulder stability, potentially contributing to symptom persistence and increasing the risk of recurrent injury. Previous research has also associated proprioceptive deficits with higher pain intensity, functional disability, and reduced neuromuscular control.

Proprioception plays a fundamental role in sensory integration and in the regulation of precise and coordinated shoulder movements. Altered afferent input from muscular and articular structures may impair dynamic stabilization mechanisms and compromise upper-limb function during sports activities.

Dry needling is a minimally invasive physiotherapy technique widely used for the treatment of myofascial trigger points. Previous studies have demonstrated positive effects of dry needling on pain and functional disability in individuals with subacromial pain syndrome. In addition, research conducted in other joints has suggested that dry needling may influence motor control, postural stability, and proprioceptive mechanisms.

Despite the growing clinical interest in this intervention, there is currently limited evidence regarding the effects of dry needling on shoulder proprioception and sensorimotor variables in individuals with SAPS, particularly in athletic populations. Therefore, further investigation is needed to determine whether adding dry needling to a therapeutic exercise program may provide additional benefits for neuromuscular control and shoulder function.

The primary aim of this clinical trial is to evaluate the effectiveness of dry needling combined with therapeutic exercise on shoulder proprioception in amateur athletes with subacromial pain syndrome. Additionally, the study will assess the potential effects of the intervention on dynamic stability, shoulder isometric strength, pain perception, and upper-limb functional disability.

A randomized controlled trial with two parallel groups will be conducted. Participants will be randomly assigned in a 1:1 ratio to:

an experimental group receiving dry needling combined with therapeutic exercise, or a control group receiving therapeutic exercise alone.

The intervention period will last 3 weeks. Participants in the experimental group will receive two dry needling sessions separated by a 10-day interval. The technique will be administered by an experienced physiotherapist with specialized training in dry needling, following a predefined protocol based on the available scientific literature.

The intervention will target myofascial trigger points located in scapulohumeral muscles commonly associated with shoulder pain and subacromial pain syndrome. Trigger points will be identified through standardized clinical examination procedures.

Both groups will perform a structured home-based therapeutic exercise program focused on muscular strengthening, neuromuscular control, and shoulder function. Participants will receive individualized instructions, and adherence to the exercise program will be monitored using follow-up records.

Outcome assessments will be performed by an evaluator blinded to group allocation in order to minimize measurement bias. Measurements will be collected at three time points: baseline, 10 days after the first intervention session, and 10 days after the second intervention session, to evaluate changes in proprioception, dynamic stability, muscular strength, pain, and functional disability.

This study aims to provide clinical evidence regarding the potential role of dry needling as an adjunct to therapeutic exercise in the management of sensorimotor and functional impairments associated with subacromial pain syndrome in athletic populations. The findings may contribute to the development of more effective therapeutic strategies aimed at improving shoulder function and optimizing functional recovery in athletes with this condition.

Inclusion Criteria:

• Men and women aged between 18 and 40 years.
• Clinical diagnosis of subacromial pain syndrome (SAPS) according to the Dutch Orthopaedic Association criteria: presence of a painful arc and at least two positive tests among the following: Hawkins-Kennedy test, Neer sign, Jobe test, Drop Arm test, or Gerber test.
• Participation in sports involving predominant upper-limb activity between 2 and 4 hours per week.

Exclusion Criteria:

• Previous surgery involving the upper extremities.
• Diagnosis of specific shoulder pathologies other than SAPS at the time of the study.
• Receipt of medical or physiotherapy treatment within the month prior to the intervention.
• Needle phobia or refusal to receive dry needling treatment.
• Presence of vestibular disorders, balance impairments, or vascular alterations that could interfere with study measurements.
• Confirmed or suspected pregnancy.

Individual participant data will not be shared due to ethical and data protection constraints under Spanish and European regulations (RGPD, Ley Orgánica 3/2018). Anonymized aggregate results will be made available through publication in peer-reviewed journals

Outcome assessors and data analysts will remain blinded to group allocation throughout the study. Due to the nature of the intervention, participants and treating physiotherapists cannot be blinded.