The main objective of this research is to evaluate the effectiveness of two interventions (PIE vs DDN) in adult patients who have suffered a LCS after a traffic accident and comparing it with a standard physiotherapy program. As a secondary objective, the investigators will analyze the reduction of intrafibrillar blood flow and muscle elasticity perceived by the patient in the long term and the reduction of pain and disability appreciated by the patient.

It is hypothesized as an alternative hypothesis that percutaneous electrolysis and/or deep dry needling intervention in combination with standard physiotherapy will give better clinical outcomes in patients with active trigger point LCS following a road traffic accident compared to the current standard physiotherapy intervention.

The researchers will compare both invasive physical therapy techniques with standard treatment to see if these techniques are more effective in treating whiplash syndrome.

The present study primarily aims to evaluate the clinical effectiveness of two invasive physiotherapy techniques-percutaneous intratissue electrolysis (PIE) and deep dry needling (DDN)-combined with conventional physiotherapy, compared to a standard physiotherapy program in adult patients who have sustained a whiplash-associated disorder (WAD) following a motor vehicle accident.

Whiplash injury is one of the most common musculoskeletal sequelae after traffic accidents, often leading to chronic pain and functional disability. The heterogeneity of clinical responses and the persistence of symptoms underscore the need for optimized therapeutic strategies supported by high-quality evidence.

This prospective, randomized controlled trial (RCT) will include three parallel intervention arms:

Control group: standard physiotherapy based on therapeutic exercise and manual therapy techniques.

Experimental group 1: standard physiotherapy + PIE intervention.

Experimental group 2: standard physiotherapy + DDN intervention.

The study population will consist of adult subjects diagnosed with WAD and the presence of active myofascial trigger points in the cervical musculature. Participants will be randomly assigned to one of the three groups, and interventions will be administered over a predetermined period, with follow-up assessments scheduled at both short- and long-term intervals.

Secondary outcomes include:

Changes in intrafibrillar blood flow Patient-reported muscle elasticity, Self-reported pain levels Functional disability

The alternative hypothesis proposes that the application of invasive techniques (PIE or DDN) as an adjunct to conventional physiotherapy will yield superior clinical outcomes in terms of pain reduction, functional improvement, and muscle parameter normalization when compared to standard physiotherapy alone.

This study aims to generate robust scientific evidence regarding the comparative efficacy of these interventions and to inform clinical decision-making in the rehabilitative management of post-traumatic whiplash-associated disorders.

Inclusion Criteria:

• Adults with whiplash syndrome following a traffic accident.
• Patients must reside or stay in the Autonomous Community of Melilla during the intervention phase.
• Subjects will have the presence of neck pain after suffering a traffic accident and the presence of at least one active trigger point in the sternocleidomastoid and/or levator scapulae muscles.
• All subjects who suffer a traffic accident and who have a score of 5 or higher on the numerical scale (EN) of pain assessment.

Exclusion Criteria:

• Patients undergoing anticoagulant treatment.
• Patients who have suffered previous cervical trauma or who have undergone surgery in the last year.
• Subjects who present some type of alteration (skin or infection, sensitivity or pain perception).
• Subjects with central or peripheral nervous system involvement.
• Patients who have problems with the material: allergy to metal, belonephobia (fear of needles).
• Pregnant women.