Nonspecific Shoulder PainNCT06958276
Effect of US-Guided PNM in CrossFit With Nonspecific Shoulder Pain
A study testing Ultrasound Guided Percutaneous Neuromodulation. Frequency of 10 Hz and Ultrasound Guided Percutaneous Neuromodulación. Frequency of 1 Hz in people with Nonspecific Shoulder Pain and Shoulder Pain Syndrome, run by Universidad de Zaragoza at 1 site in Spain.
Trial summary
CrossFit is a high-intensity physical training program that combines exercises from various disciplines, such as weightlifting, track and field, running, and gymnastics. The three main characteristics of this sport discipline are as follows: first, the execution of functional movements; second, performing them at high… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Nonspecific Shoulder Pain, Shoulder Pain Syndrome
- What is being tested?
- Ultrasound Guided Percutaneous Neuromodulation. Frequency of 10 Hz and Ultrasound Guided Percutaneous Neuromodulación. Frequency of 1 Hz
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 42 participants
- Where
- 1 siteSpain
- Study dates
- 1 May 2025to 31 Jul 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Be over 18 years old.
- Have shoulder pain lasting more than 3 months.
- The pain must not have an apparent cause, meaning there is no specific diagnosis, and thus it is considered nonspecific pain.
- Train CrossFit at least 3 days per week.
Who cannot join
- Have received any medical or physiotherapy treatment for nonspecific shoulder pain.
- Have had previous shoulder surgery.
- Present fear of needles (belonephobia) or fear of the US-guided PNM intervention.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Changes in Shoulder Strength, Mobility, and Muscle Recruitment Following Ultrasound-Guided Percutaneous Neuromodulation in CrossFit Athletes With Nonspecific Shoulder Pain: A Randomized Controlled Trial
CrossFit is a high-intensity physical training program that combines exercises from various disciplines, such as weightlifting, track and field, running, and gymnastics. The three main characteristics of this sport discipline are as follows: first, the execution of functional movements; second, performing them at high intensity; and lastly, constant variation. This training model has shown improvements in strength, power, balance, flexibility, and cardiorespiratory capacities.
There are various risk factors described in the literature that may lead to injuries in CrossFit athletes. It has been suggested that demanding training programs increase this risk, especially when performed incorrectly (poor technique). Additionally, excessive training load and frequency can lead to early fatigue, greater perceived effort, and risky movement execution.
Read more
On the other hand, older age, male sex, and previous injuries also appear to be relevant risk factors, as well as performing stretches prior to CrossFit practice. Several studies have shown that the shoulder is the joint with the highest prevalence of injury in this sport, surpassing other commonly affected joints such as the lumbar spine or the knee.
Among the wide variety of injuries related to the shoulder, the diagnosis of "nonspecific shoulder pain" has a high prevalence in the adult population. This term is used to describe clinical cases where it is not possible to identify the specific cause of the pain, and is justified by its multifactorial etiology, which is associated with several risk factors. These include: imbalance in the strength ratio between internal and external rotators, limitations in rotational mobility of the glenohumeral joint, deficits in motor control of the scapular musculature, shoulder muscle fatigue, and the repetitive execution of overhead exercises.
This last factor is especially relevant in the CrossFit population, as such movements are frequent in the discipline. Repeated overhead exercises have been associated with a deficit in glenohumeral internal rotation. From a biomechanical perspective, this movement is more efficient when accompanied by external rotation, so internal rotation limitation can compromise the motion. This deficit has been linked to modifiable musculoskeletal factors such as posterior capsule stiffness, shortening of the infraspinatus or teres minor muscles, and scapular mechanics alterations, as well as non-modifiable factors like bone torsion observed in young athletes. These conditions can lead to pain and/or glenoid labrum pathology.
Regarding the clinical management of nonspecific shoulder pain, conservative physiotherapy treatment is the most common approach. This is based on manual therapy and therapeutic exercise. However, in recent years, invasive physiotherapy has gained popularity in the treatment of musculoskeletal disorders through techniques such as ultrasound-guided percutaneous neuromodulation (US-guided PNM). This technique involves delivering electrical stimulation through an acupuncture needle placed near the nerve (epineurium) or the motor point of the target muscle, aiming to restore proper functionality of pathological neuromuscular structures.
US-guided PNM, applied to both the lower and upper limbs, has shown effectiveness in both healthy individuals and subjects with various musculoskeletal disorders, improving pain, strength, flexibility, and normalization of neural excitability.
Currently, there are therapeutic exercise protocols used for both evaluation and treatment of nonspecific shoulder pain in CrossFit athletes. Additionally, there are US-guided PNM protocols that have been applied to healthy CrossFit athletes and have demonstrated improvements in shoulder rotational strength. However, US-guided PNM has not yet been studied in a population of CrossFit athletes with nonspecific shoulder pain. Therefore, this randomized clinical trial aims to evaluate the effectiveness of two different US-guided PNM protocols, analyzing which methodology is most appropriate for reducing the risk factors associated with the development of nonspecific shoulder pain in CrossFit athletes.
- Conditions
- Nonspecific Shoulder Pain, Shoulder Pain Syndrome
- Being tested
- Ultrasound Guided Percutaneous Neuromodulation. Frequency of 10 Hz, Ultrasound Guided Percutaneous Neuromodulación. Frequency of 1 Hz
- Keywords
- neuromodulation, percutaneous, ultrasound, axillary nerve, suprascapular nerve
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Ultrasound Guided Percutaneous Neuromodulation. Frequency of 10 HzOther
The US-guided PNM intervention will be performed with the patient in the prone position, the shoulder to be treated flexed at 90 degrees, the humerus partially supported on the table, the elbow flexed at 90 degrees, and the musculature relaxed. Needles will be inserted near the perineurium of the axillary and suprascapular nerves. Prior to needle insertion, the skin will be cleaned with isopropyl alcohol and chlorhexidine. The PNM intervention will consist of applying a compensated asymmetric biphasic current, with a rectangular positive phase and a triangular negative phase, at a frequency of 10 Hz, pulse width of 240 μs, and the maximum tolerated intensity that elicits a painless maximal muscle contraction, following this protocol: 10 stimulations of 10 seconds each, with a 10-second rest between stimulations.
Ultrasound Guided Percutaneous Neuromodulación. Frequency of 1 HzOther
Same intervention as previously described, with the only difference being that the frequency will be 1 Hz instead of 10 Hz.
| Study group | Role | What they receive |
|---|---|---|
| US-guided PNM 10 Hz | Experimental | One session of US-guided PNM at a frequency of 10 Hz. Receives: Other: Ultrasound Guided Percutaneous Neuromodulation. Frequency of 10 Hz |
| US-guided PNM 1 Hz | Experimental | One session of US-guided PNM at a frequency of 1 Hz. Receives: Other: Ultrasound Guided Percutaneous Neuromodulación. Frequency of 1 Hz |
What is being measured
The primary outcome is the main question the study is designed to answer.
Strength ratio between ER/IR
A hand-held dynamometer (HHD) with units in kg of force (KgF) was used. The participant was positioned according to the instructions of Hams et al., seated with the hip and knee flexed at 90 degrees, feet flat on the floor, trunk upright, shoulder at 0 degrees of abduction and neutral rotation, and elbow in contact with the trunk, flexed at 90 degrees. The dynamometer was placed on the distal third of the inner forearm to assess internal rotation (IR) and on the distal third of the outer forearm to assess external rotation (ER). Athletes were instructed to produce the maximum isometric force for 10 seconds, while the evaluator applied the same force in the opposite direction. Three tests were performed bilaterally, with a one-minute rest between each test, and the final data was the average of the three tests. The strength ratio was calculated by dividing ER/IR, with 2:3 (0.66) considered the ideal ratio.
Measured: The measurements were taken pre-intervention and immediately post-intervention.
Secondary outcomes (2)
Glenohumeral rotational mobility
A digital goniometer (HALO), which has demonstrated validity and reliability for measurements in the shoulder joint, was used. For each participant, bilateral internal rotation (IR) and external rotation (ER) were measured. Subsequently, both rotations were summed to create a third variable: the total rotational movement arc (ART). The patient was placed in the supine position, with the shoulder abducted at 90 degrees, the elbow flexed at 90 degrees, and the forearm perpendicular to the floor. An evaluator stabilized the scapula by applying pressure to the coracoid process, while another evaluator performed passive internal/external rotation and placed the goniometer on the distal third of the forearm on its dorsal side. Passive mobilization was completed when the first "end-feel" was reached or when the scapula began to move. Two measurements of each rotation were taken on each shoulder, and the final data was the average of both measurements.
Measured: The measurements were taken pre-intervention and immediately post-intervention.
Scapular motor control
A surface electromyograph from the commercial brand Mdurance, which has been validated and used in the literature, was used. According to Kibler et al., proper scapular motor control is primarily achieved through the upper and lower trapezius muscles and the serratus anterior. Therefore, surface electrodes were placed bilaterally on the three muscles mentioned, and the athlete was asked to perform five repetitions of glenohumeral abduction in the scapular plane. The electromyograph software recorded the activation level of the three muscles, as well as the order of activation of the musculature.
Measured: The measurements were taken pre-intervention and immediately post-intervention.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 May 2025
- Study start1 May 2025
- Primary completion1 Jun 2025
- Study completion31 Jul 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Nonspecific Shoulder PainStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 42 participants (actual)
Sponsor and investigators
- Lead sponsor
- Universidad de Zaragoza
- Sponsor type
- University, hospital or other
- Collaborators
- Aragon Institute for Health Research (IIS Aragón)
- Responsible party
- Principal investigator, Alberto Carcasona Otal, Universidad de Zaragoza
- Investigators
- Alberto Carcasona, Physiotherapist, Principal investigator, IIS Aragón, University of Zaragoza
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06958276
- Sponsor's protocol ID
- NMP-e, CrossFit, dolor hombro
- Status last verified
- Aug 2025
- First submitted
- 19 Apr 2025
- Last updated
- 2 Sep 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Data will be shared on a reasonable request contacting with the main author once data has been published. Anyway, Individual participant data (IPD) will be shared with other researchers in accordance with data sharing protocols and participant consent, ensuring confidentiality and ethical considerations are maintained.
Study at a glance
From the registry record, last updated by the sponsor on 2 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Changes in Shoulder Strength, Mobility, and Muscle Recruitment Following Ultrasound-Guided Percutaneous Neuromodulation in CrossFit Athletes With Nonspecific Shoulder Pain: A Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT06958276
- Acronym / sponsor ID
- NMP-e, CrossFit, dolor hombro
- Conditions
- Nonspecific Shoulder Pain, Shoulder Pain Syndrome
- Keywords
- neuromodulation, percutaneous, ultrasound, axillary nerve, suprascapular nerve
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 42 participants (actual)
- Lead sponsor
- Universidad de ZaragozaUniversity, hospital or other
- Collaborators
- Aragon Institute for Health Research (IIS Aragón)
- Study start
- 1 May 2025 (actual)
- Primary completion
- 1 Jun 2025 (actual)
- Study completion
- 31 Jul 2025 (actual)
- First posted
- 6 May 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
CrossFit is a high-intensity physical training program that combines exercises from various disciplines, such as weightlifting, track and field, running, and gymnastics. The three main characteristics of this sport discipline are as follows: first, the execution of functional movements; second, performing them at high intensity; and lastly, constant variation. This training model has shown improvements in strength, power, balance, flexibility, and cardiorespiratory capacities.
There are various risk factors described in the literature that may lead to injuries in CrossFit athletes. It has been suggested that demanding training programs increase this risk, especially when performed incorrectly (poor technique). Additionally, excessive training load and frequency can lead to early fatigue, greater perceived effort, and risky movement execution.
On the other hand, older age, male sex, and previous injuries also appear to be relevant risk factors, as well as performing stretches prior to CrossFit practice. Several studies have shown that the shoulder is the joint with the highest prevalence of injury in this sport, surpassing other commonly affected joints such as the lumbar spine or the knee.
Among the wide variety of injuries related to the shoulder, the diagnosis of "nonspecific shoulder pain" has a high prevalence in the adult population. This term is used to describe clinical cases where it is not possible to identify the specific cause of the pain, and is justified by its multifactorial etiology, which is associated with several risk factors. These include: imbalance in the strength ratio between internal and external rotators, limitations in rotational mobility of the glenohumeral joint, deficits in motor control of the scapular musculature, shoulder muscle fatigue, and the repetitive execution of overhead exercises.
This last factor is especially relevant in the CrossFit population, as such movements are frequent in the discipline. Repeated overhead exercises have been associated with a deficit in glenohumeral internal rotation. From a biomechanical perspective, this movement is more efficient when accompanied by external rotation, so internal rotation limitation can compromise the motion. This deficit has been linked to modifiable musculoskeletal factors such as posterior capsule stiffness, shortening of the infraspinatus or teres minor muscles, and scapular mechanics alterations, as well as non-modifiable factors like bone torsion observed in young athletes. These conditions can lead to pain and/or glenoid labrum pathology.
Regarding the clinical management of nonspecific shoulder pain, conservative physiotherapy treatment is the most common approach. This is based on manual therapy and therapeutic exercise. However, in recent years, invasive physiotherapy has gained popularity in the treatment of musculoskeletal disorders through techniques such as ultrasound-guided percutaneous neuromodulation (US-guided PNM). This technique involves delivering electrical stimulation through an acupuncture needle placed near the nerve (epineurium) or the motor point of the target muscle, aiming to restore proper functionality of pathological neuromuscular structures.
US-guided PNM, applied to both the lower and upper limbs, has shown effectiveness in both healthy individuals and subjects with various musculoskeletal disorders, improving pain, strength, flexibility, and normalization of neural excitability.
Currently, there are therapeutic exercise protocols used for both evaluation and treatment of nonspecific shoulder pain in CrossFit athletes. Additionally, there are US-guided PNM protocols that have been applied to healthy CrossFit athletes and have demonstrated improvements in shoulder rotational strength. However, US-guided PNM has not yet been studied in a population of CrossFit athletes with nonspecific shoulder pain. Therefore, this randomized clinical trial aims to evaluate the effectiveness of two different US-guided PNM protocols, analyzing which methodology is most appropriate for reducing the risk factors associated with the development of nonspecific shoulder pain in CrossFit athletes.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| US-guided PNM 10 Hz | Experimental | Other: Ultrasound Guided Percutaneous Neuromodulation. Frequency of 10 HzOne session of US-guided PNM at a frequency of 10 Hz. |
| US-guided PNM 1 Hz | Experimental | Other: Ultrasound Guided Percutaneous Neuromodulación. Frequency of 1 HzOne session of US-guided PNM at a frequency of 1 Hz. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Be over 18 years old.
- Have shoulder pain lasting more than 3 months.
- The pain must not have an apparent cause, meaning there is no specific diagnosis, and thus it is considered nonspecific pain.
- Train CrossFit at least 3 days per week.
Key exclusion criteria (3 listed)
- Have received any medical or physiotherapy treatment for nonspecific shoulder pain.
- Have had previous shoulder surgery.
- Present fear of needles (belonephobia) or fear of the US-guided PNM intervention.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Ultrasound Guided Percutaneous Neuromodulation. Frequency of 10 HzThe US-guided PNM intervention will be performed with the patient in the prone position, the shoulder to be treated flexed at 90 degrees, the humerus partially supported on the table, the elbow flexed at 90 degrees, and the musculature relaxed. Needles will be inserted near the perineurium of the axillary and suprascapular nerves. Prior to needle insertion, the skin will be cleaned with isopropyl alcohol and chlorhexidine. The PNM intervention will consist of applying a compensated asymmetric biphasic current, with a rectangular positive phase and a triangular negative phase, at a frequency of 10 Hz, pulse width of 240 μs, and the maximum tolerated intensity that elicits a painless maximal muscle contraction, following this protocol: 10 stimulations of 10 seconds each, with a 10-second rest between stimulations. | Other | US-guided PNM 10 Hz |
| Ultrasound Guided Percutaneous Neuromodulación. Frequency of 1 HzSame intervention as previously described, with the only difference being that the frequency will be 1 Hz instead of 10 Hz. | Other | US-guided PNM 1 Hz |
Primary outcome
Strength ratio between ER/IR
Time frame: The measurements were taken pre-intervention and immediately post-intervention.
A hand-held dynamometer (HHD) with units in kg of force (KgF) was used. The participant was positioned according to the instructions of Hams et al., seated with the hip and knee flexed at 90 degrees, feet flat on the floor, trunk upright, shoulder at 0 degrees of abduction and neutral rotation, and elbow in contact with the trunk, flexed at 90 degrees. The dynamometer was placed on the distal third of the inner forearm to assess internal rotation (IR) and on the distal third of the outer forearm to assess external rotation (ER). Athletes were instructed to produce the maximum isometric force for 10 seconds, while the evaluator applied the same force in the opposite direction. Three tests were performed bilaterally, with a one-minute rest between each test, and the final data was the average of the three tests. The strength ratio was calculated by dividing ER/IR, with 2:3 (0.66) considered the ideal ratio.
2 secondary outcomes
Glenohumeral rotational mobility
Time frame: The measurements were taken pre-intervention and immediately post-intervention.
Scapular motor control
Time frame: The measurements were taken pre-intervention and immediately post-intervention.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Sep 2025.
- Individual participant dataSharing planned: Yes. Data will be shared on a reasonable request contacting with the main author once data has been published. Anyway, Individual participant data (IPD) will be shared with other researchers in accordance with data sharing protocols and participant consent, ensuring confidentiality and ethical considerations are maintained.
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Alberto Carcasona, Physiotherapist principal investigator
IIS Aragón, University of Zaragoza
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Ultrasound Guided Percutaneous Neuromodulation. Frequency of 10 Hz and Ultrasound Guided Percutaneous Neuromodulación. Frequency of 1 Hz in people with Nonspecific Shoulder Pain and Shoulder Pain Syndrome, run by Universidad de Zaragoza at 1 site in Spain.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 2 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Spain. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Strength ratio between ER/IR (time frame: The measurements were taken pre-intervention and immediately post-intervention.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Sep 2025.