Dry Needling in United States Doctor of Physical Therapy Programs: Safety Assessment and Adverse Event Reporting

Supplemental Digital Content is Available in the Text.

Abstract

Introduction.

Despite the growing clinical use of dry needling (DN) among physical therapists in the United States and its gradual adoption into entry-level Doctor of Physical Therapy (DPT) programs, limited research exists on DN safety within educational settings. This study aims to report the type and incidence of adverse events (AEs) associated with DN instruction in DPT programs.

Review of Literature.

To date, there has been no reporting on DN-related AEs during DPT education, making the relative risk of DN education unclear.

Subjects.

Three hundred thirty-eight students and 10 faculty members from 10 US DPT programs.

Methods.

Questionnaires and structured interviews investigated the type and incidence of AEs during DN instruction in DPT programs. Students documented prelaboratory comfort levels with DN and AEs experienced by their partners during laboratory practice. Postlaboratory interviews with DPT faculty gathered insights into AEs during instruction. Statistical methods included descriptive frequencies of AEs and reported pain. The AEs were classified as side effects, minor, moderate, or major, and were reported as percentages of total needle insertions and by body region.

Results.

Among 338 DPT students (mean age = 26.3 years), no major or moderate AEs were recorded over 1,173 needle insertions and 16 muscle areas. The most reported side effects were soreness (48%) and pain (37%). Pain was self-reported by 50% of students, with the majority experiencing low levels (0–3/10) on the numerical pain rating scale. Lower prelaboratory comfort levels were reported between those who experienced a minor AE and those who did not (P = .030). Side effects and minor AEs in DPT education appeared to closely resemble those in clinical settings.

Discussion and Conclusion.

Student safety performing DN was high, with no major AEs reported. Faculty self-selection of muscle areas may have influenced major AE reporting. Findings suggest that DN can be safely included within DPT education, with risks similar to those in clinical practice.

INTRODUCTION

Dry needling (DN) is defined as a skilled intervention that uses a thin filiform needle to treat neuromusculoskeletal pain and movement impairments by targeting myofascial trigger points in muscles and connective tissues.¹ As the frequency of clinical utility of DN increases for physical therapists in the United States, DN instruction has been slowly adopted into entry-level Doctor of Physical Therapy (DPT) programs. Despite its growing use, there has been limited research on DN within educational settings. A recent survey of 75 programs² found that 40 of those programs integrated DN into their curriculum, with another 8 in the planning stage. Of these, only 21 included laboratory practice.² To date, there has been no investigation into the safety of DN within entry-level DPT education programs, making the relative risk of DN education currently unclear. DPT faculty and students should be adequately informed to understand these risks to provide safe DN instruction. Therefore, the purpose of this study is to report the type and incidence of adverse events (AEs) associated with DN instruction in DPT education.

REVIEW OF LITERATURE

Incidence of Adverse Events

Three research teams^3-5 examined DN treatment–related side effects and AEs during physical therapy treatment. They reported that side effects, including bleeding, bruising, and pain, were common, with an incidence ranging from 19% to 39.6%. The most frequently reported side effects included bleeding (7.5–17.1%), bruising (4.6–11.8%), pain during treatment (3.0–39.6%), and pain after treatment (2.2–23.4%). Other less common minor AEs include feeling faint (0.2–0.8%), drowsiness (0.3–2.1%), headache (0.1–2.2%), and nausea (0.1–2.1%).^3-5

A vasovagal response, or neurally mediated syncope, involves an autonomic reaction to stimuli such as fear, pain, or the sight of blood.⁶ This response increases parasympathetic activity, leading to lightheadedness or syncope. Reports indicate that fainting is one of the more commonly reported moderate AEs, with instances noted at 0.02% of total treatments.³ Approximately 27.1% of surveyed practitioners encountered at least one case of DN-related fainting during their career, emphasizing the importance of monitoring patients for signs of anxiety and autonomic responses during DN procedures.⁵

Moderate and major AEs are rare and have been documented as < 0.1% of DN treatments.³ The reported incidence varies, ranging from zero major AEs throughout 7,629 DN treatments⁴ to 20 over 20,464 treatments, with the most common being prolonged aggravation of symptoms, fainting, and forgotten needles.³ In contrast, others⁵ reported 407 moderate and major AEs over the lifetime careers of 413 physical therapists. Pneumothorax, albeit rare, is among the most serious AE and has been reported in both acupuncture and DN literature.^7-9 This condition requires immediate medical attention and can range in severity from needing simple observation to requiring hospitalization.

Considerations for Doctor of Physical Therapy Student Anxiety

As more DPT programs adopt DN into their curricula, examining the students’ responses to administering needles or being dry-needled during their education should be considered. Needle phobia is defined by the Diagnostic and Statistical Manual of Mental Disorders-5-TR as a psychiatric disorder involving the avoidance of needles.¹⁰ It often causes a systemic reaction, including a vasovagal response and decreased blood pressure, which can lead to fainting.^11,12 Interestingly, individuals can be genetically predisposed to vasovagal syncope.¹³ When combined with needle phobia, these individuals are more likely to faint during procedures involving needles.¹⁴ Needle fear is more common and describes anxiety associated with needles and in situations where needles are used.¹⁵ The prevalence of needle fear ranges from 20% to 30% in young adults aged 20–40 and decreases as age increases, with <5% prevalence in adults 80 years and older.¹⁵ Needle fear is more prevalent in females, especially in females less than 40 years of age.^15,16 Those with needle fear were significantly more likely to experience minor AEs such as dizziness, nausea, and faintness compared to those without fear. In addition, the anxiety level is predictive of fainting during blood draws in donors who have needle fear.^17,18 Students in health care programs have shown needle fear, with a higher prevalence in students with anxiety.¹⁹ The combination of younger age and anxiety could have the potential for more minor AEs associated with needle fear in DPT educational programs.

Categorizing Adverse Events

There is significant variability in the definitions of DN AEs, with no universally accepted method for categorizing them.^3,20-22 To understand and report AEs effectively for this project, they were operationally defined into 3 groups based on the language by Kearns et al.²²

• Major/Moderate AEs: Serious and/or unacceptable events that require further medical consultation. Examples include pneumothorax, forgotten needle, nerve injury, and fainting.

• Minor AEs: Not serious and involve transient worsening of symptoms. Examples include feeling faint, nausea, headache, and drowsiness.

• Not AEs/Side Effects: Anticipated, expected, and acceptable side effects, such as pain, bleeding, bruising, and soreness.

METHODS

This project was a descriptive and exploratory survey with electronically distributed pre- and postinstruction questionnaires and structured interviews investigating the type and incidence of AEs associated with DN instruction in DPT programs.

Sampling Methodology and Recruitment

Participants included DPT faculty and students. A recruitment email was sent electronically to all American Council of Academic Physical Therapy (ACAPT) members, requesting to forward the email to the faculty member who instructed DN. In addition, the link to participate in the study was shared via LinkedIn. Inclusion criteria for DPT faculty were (1) currently instructing in a DPT program in the United States and (2) teaching a DPT program course in which DN was instructed, including a laboratory experience, and for DPT students: (1) currently enrolled in a DPT program in the United States and (2) participating in a DPT program course in which DN was instructed. Faculty members voluntarily agreed to participate in the study electronically and consented. A script defining AEs was emailed to each faculty member before their course, along with a link to the consent form and survey for each student. Students consented separately at the start of their DN laboratory session. Students were not required to participate, nor did the instructors know which students did or did not consent to participate in the survey.

Data Collection

Data collection was conducted using a web-based Qualtrics Survey, provided as Supplemental Digital Content (Supplemental Material A, http://links.lww.com/JOPTE/A343), and virtual interviews. Figure 1 outlines the research process for faculty and student participants. The faculty member was asked to read or post the script defining AEs to the class before starting the DN laboratory. At the beginning of the DN laboratory session, students answered questions related to the safety and comfort level of DN found in Section 1. During the DN laboratory session, students completed Section 2, documenting muscle structure, number of needle insertions, and AEs. At the conclusion of the laboratory session, all DPT students completed Section 3. The survey was adapted from previous work by Boyce et al.³ A recent Delphi study²³ identified which AEs should be included in informed consent in clinical practice. Experts agreed upon 14 AEs, all of which were included in our study. The survey was sent to 3 content experts before distribution to assess face validity and 3 current DPT students for feedback on ease of use. Modifications were made to include a rating scale for “not adverse” and “minor AE.” Within 1 month after the DN laboratory, each instructor was interviewed virtually, and each session was recorded using Zoom. Key questions were asked to confirm the occurrence and assess the management of AEs during DN instruction. Faculty were first asked whether any moderate or major AEs occurred, and if so, to describe the events and suggest ways to reduce their incidence. They were also asked to identify the most common side effects or mild AEs observed and to offer suggestions for minimizing these in future laboratory sessions. These questions sought insights on improving DN safety and student comfort during instruction.

Figure 1. Flowchart for (A) Faculty and (B) Student Participants. ACAPT = American Council of Academic Physical Therapy; AE = Adverse Event; DN = Dry Needling.

Statistical Analysis

Demographic data, including age, sex, and ethnicity, were recorded for the DPT students participating in the survey using descriptive analyses. Potential group differences in baseline demographics for participants and DPT student aggregate data from the Commission on Accreditation in Physical Therapy Education (CAPTE) were tested using the Chi-square test. Frequency counts of AEs and pain were recorded. AEs rated as side effects, minor, and moderate/major were reported as a percentage of the total number of needle insertions performed by all students. In addition, each AE was reported as a percentage of total AEs and a percentage per body region. Chi-square goodness of fit was used to test the difference between observed and expected frequencies of percent AEs in this study compared to the literature.^3-5 The Mann–Whitney U test examined the difference in prelaboratory comfort levels between students who experienced a minor AE and those who did not. Significance was set at α = 0.05. Quantitative data were analyzed using SPSS v28 and Excel version 2022. Qualitative data from faculty interviews were analyzed using ATLAS.ti version 23.

RESULTS

Our survey, distributed electronically to ACAPT members representing over 256 institutions and through LinkedIn, yielded responses from 35 institutions, with an estimated response rate of 13%. Of these responses, 10 met the inclusion criteria. DPT faculty and student data were collected from 10 entry-level DPT programs spanning 6 geographical regions, encompassing both residential and hybrid formats. Seven courses included DN education within a required course, with 3 offering it as an elective. The study included 338 DPT student participants, 57.5% female, with an average age of 26.3 years (SD = 4.7; range 21–50). Demographic details, including age and ethnicity, demonstrate similarities (P = .999) to typical DPT cohorts compared to CAPTE aggregated data.²⁴

Side Effects and Adverse Event Reporting

No major or moderate AEs were reported among the 1,173 needle insertions recorded over 16 muscle areas. The most commonly reported side effect was soreness, 48%, followed by pain reported by 37%. Bleeding occurred in 9% of total needle insertions, with bruising at 1%. Detailed frequency counts for needle insertions and AEs can be found in Tables 1 and 2. The prevalence of each side effect and minor AE were recorded and compiled across body regions. The upper extremity exhibited the highest rate of side effects, while the spine demonstrated the fewest. Detailed results can be found in Table 3.

Table 1.

Total Needle Insertions Per Body Area

Lower Extremity		Upper Extremity		Spine
Gastrocnemius	113	Infraspinatus	39	Lumbar multifidus	12
Quadriceps	321	Deltoid	63	Upper trapezius	38
Hamstrings	109	Wrist extensors	33	Levator scapulae	15
Gluteus medius	204	Hand/thumb	6	Cervical paraspinals	105
Piriformis	11			Suboccipitals	91
Tensor fasciae latae	8
Adductors	5
TOTAL	771		141		261

Table 2.

Types of Side Effects and Minor AEs Reported Among 702 Treatments and 1,173 Insertions

	Student Report Across All Muscle Areas	Number per 100 Treatments (%)	Percent of Total Insertions (%)
Bleeding at the needling site	110	15.67	9.38
Bruising	17	2.42	1.45
Pain during	260	37.04	22.17
Pain after	75	10.68	6.39
Soreness	338	48.15	28.82
Aggravation of symptoms	6	0.85	0.51
Feeling faint	6	0.85	0.51
Nausea	5	0.71	0.43
Headache	1	0.14	0.09
Drowsiness	2	0.28	0.17
Other	23	3.28	1.96

Abbreviation: AE = adverse event.

Table 3.

Prevalence of Side Effects and Minor AEs Per Body Region

	Lower Extremity (%)	Upper Extremity (%)	Spine (%)
Bleeding at the needling site	10.25	13.48	4.60
Bruising	1.69	1.42	0.77
Pain during	23.61	29.08	14.18
Pain after	5.97	11.35	4.98
Soreness	33.46	37.59	10.34
Feeling faint	0.78	0.00	0.00
Nausea	0.52	0.71	0.00
Headache	0.13	0.00	0.00
Drowsiness	0.13	0.00	0.38
Aggravation of symptoms	0.26	2.13	0.38

Abbreviation: AE = adverse event.

Minor AEs reported included 6 instances of students feeling faint, 5 cases of nausea, 2 instances of drowsiness, and one complaint of headache. These 14 events were reported by 10 individual student participants, with some reporting feeling both faint and nausea. The minor AEs were generally mild, with an average level of 2.5 reported on a 1–10 scale. Of the 10 students (median age 25 years) who reported minor AEs, 70% were female, a higher proportion than the overall sample (57.5%). When asked the question, “How comfortable do you feel having a classmate perform DN on you today?” a difference in the mean score was reported between those who experienced a minor AE and those who did not, with a mean of 3.20 and 2.25, respectively (P = .030). Figure 2 illustrates the difference in the distribution between groups. Follow-up interviews with DPT faculty confirmed the absence of moderate and major AEs. Faculty provided detailed elaboration on student responses, noting additional reactions, including 2 instances of crying. Cases of “feeling faint” were confirmed, while actual “fainting” was absent. Three faculty members reported establishing a designated recovery area with a treatment table for managing potential vasovagal reactions.

Figure 2. The Distribution of Prelaboratory Comfort Levels Among Students Who Experienced Minor AEs Compared to Those Who Did Not. AE = Adverse Event.

Pain experienced during treatment was reported by the student's partner and self-reported by the student after the DN laboratory. While 50% of students self-reported experiencing pain, only 37% reported their partner experiencing pain during the procedure. In addition, 83.8% of students reported their pain intensity between 0 and 3 out of 10 on the numerical pain rating scale (NPRS). No student reported experiencing pain greater than 7 out of 10. Not all students who reported a minor AE reported pain, with 30% reporting no pain experienced.

Table 4 presents the frequencies of observed AEs in DPT education, contrasted with those in clinical practice. Most side effects and minor AEs observed in DPT education closely resembled those encountered in clinical settings, with one notable exception: pain during treatment, which exhibited a higher prevalence among DPT students than PT patients.^3-5 A Chi-square test was conducted to assess the frequencies between DPT students and PT patients, yielding a nonsignificant relationship between these variables (P = .243).

Table 4.

Difference in Observed Side Effects and AE Frequencies in DPT Education Compared to Clinical Practice

	Student Report: Across All Muscle Areas	DPT Students: Number Per 100 Treatments (%)	PT Patients: Number Per 100 Treatments (%)3	PT Patients: Number Per 100 Treatments (%)4	PT Patients: Estimated Percentage (%)5
Pain during	260	37.04	5.93	3.01	39.56
Pain after	75	10.68	2.72	2.19	23.38
Bleeding at the needling site	110	15.67	16.04	7.55	17.11
Bruising	17	2.42	7.71	4.65	11.81
Aggravation of symptoms	6	0.85	1.52	0.88	n/a
Feeling faint	6	0.85	0.78	0.22	n/a
Nausea	5	0.71	0.46	0.13	n/a
Headache	1	0.14	0.65	0.14	2.15
Drowsiness	2	0.28	0.93	0.26	2.13

Abbreviations: AE = adverse event; DPT = Doctor of Physical Therapy.

DISCUSSION

This is the first study to comprehensively describe the safety of DN instruction within US entry-level DPT programs. The results revealed the absence of major or moderate AEs during DN education, indicating acceptable student safety.

The main difference in the AEs reported in DPT education was the lack of moderate or major AEs across 1,173 needle insertions within 702 treatments. Within the clinical population, major AEs were reported for a rate of <0.1%, which equates to roughly 1 per 1,024 treatments.³ Although safety should remain the first priority, these findings suggest that DN can be effectively and safely taught in DPT programs without incurring greater risks than those observed in clinical practice.

This study also identified uncommon minor AEs during DN instruction, such as instances of students feeling faint, nausea, and headache, which may warrant further attention. Although fainting was not reported within our sample, feeling faint and nausea were reported, indicating that fainting may be a potential risk in this population. The discomfort associated with needle fear can trigger vasovagal responses such as faintness, nausea, headache, and drowsiness, which were reported by some students. A difference in comfort levels between groups was observed for those students who experienced a minor AE during the laboratory session. This aligns with previous research suggesting that anxiety and discomfort can predict AEs involving needles.^17,18,25,26 The finding that 70% of the students who reported minor AEs were female, compared to the overall sample proportion of 57.5% females, suggests a potential sex difference in needle-related anxiety and subsequent AEs. This sex difference aligns with the broader literature suggesting higher anxiety and needle fear prevalence in females, particularly in younger adults.^15,16 Investigating the effectiveness of various interventions for reducing needle fear and anxiety in DPT students may provide valuable insights for curriculum development. In addition, understanding the role of demographic factors such as age, sex, and previous experiences with needles may help tailor educational approaches to meet the unique needs of students. Despite the higher level of anxiety within the DPT student population, the safety of DN instruction was effectively maintained.

There was an incidence of side effects from DN instruction in DPT programs, similar to that seen in the clinical population.³ The average ratio of side effects and minor AEs for a patient population reported in the literature was approximately 1 event for every 2 patients.³ The reported side effects in DPT education closely resembled what is reported in the literature in clinical settings, with pain, bleeding, and bruising being most reported. Three studies^3-5 reported that side effects, including bleeding, bruising, and pain, were common in clinical practice, with an incidence ranging from 19% to 39.6%. Most students rated their pain intensity between 0 and 3 out of 10 on the NPRS, indicating that the pain associated with DN in this context is generally mild. In addition, no student reported pain greater than 7 out of 10, suggesting that severe pain is rare during DN treatment in this setting. Various demographic factors were examined to assess if they influenced the level of pain students felt during DN. However, no relationships were found. Our results pose considerations for implementing DN education within the curriculum by highlighting areas that produced more or less student discomfort. The upper extremity produced the highest rate of side effects, specifically the wrist extensors, which caused pain, soreness, and bleeding compared to other areas. In addition, the gastrocnemius and upper trapezius produced frequent pain and soreness. Areas that produced very low levels of student discomfort were the quadriceps, gluteus medius, and hamstrings.

Limitations

This study had several limitations. First, faculty self-selection of muscle areas may have influenced the reporting of major AEs. Life-threatening events like pneumothorax can only occur if needling is done over the lung field.^7,27 No programs included thoracic paraspinals or intercostals within their education, with only elective courses including the levator scapulae. This selective inclusion of muscle areas could have led to the lack of major AEs, given the emphasis on safer regions away from visceral structures and large vessels during laboratory sessions. In addition, faculty self-selection of the DN technique could have influenced the rate of AEs. For example, DN with needles in situ is less aggressive than the pistoning and twisting techniques.

The study did not account for preexisting anxiety levels unrelated to needle fear, which could influence the reporting of AEs. A more detailed assessment of baseline anxiety could provide clearer insights into the specific impact of needle fear. While the study identifies the need for interventions to address needle fear, it did not evaluate specific strategies or their effectiveness. Future research should investigate various approaches to reducing anxiety and improving comfort levels in DN education.

In addition, the inability to measure a complete sample of DPT programs that include DN could have limited our reporting. However, the response rate from Matthews et al² suggests only 21 DPT programs include a DN laboratory. This highlights that the number of DPT programs that include DN laboratory experiences may still be unknown. Furthermore, the reliance on self-reported data from students and faculty introduces the potential for response bias, wherein participants may underreport or overreport certain experiences or perceptions.

CONCLUSION

While safety should remain the first priority, our findings suggest that DN can be included with a low risk of AEs within DPT education, presenting no greater risk than that typically observed in the clinical population. Our study reports the prevalence of AEs associated with DN education, which were minor in nature and consistent with those observed in clinical practice. DPT faculty should consider selecting muscle areas with fewer side effects to enhance student comfort during laboratory practice.

Supplementary Material

jte-39-348-s001.pdf ^{(98.2KB, pdf)}

FUNDING

Nil.