The relative risk to the femoral nerve as a function of patient positioning: potential implications for trigger point dry needling of the iliacus muscle

ABSTRACT

Objectives: Prudent dry needling techniques are commonly practiced with the intent to avoid large neurovascular structures, thereby minimizing potential excessive bleeding and neural injury. Patient position is one factor thought to affect the size of the safe zone during dry needling of some muscles. This study aimed to compare the size of the needle safe zone of the iliacus muscle during two different patient positions using ultrasound imaging.

Methods: The distance from the anterior inferior iliac spine (AIIS) to the posterior pole of the femoral nerve was measured in 25 healthy participants (11 male, 14 female, mean age = 40) in both supine and sidelying positions using a Chison Eco1 musculoskeletal ultrasound unit. The average distance was calculated for each position and a two-tailed, paired t-test (α < 0.05) was used to examine the difference between positions.

Results: The mean distance from the AIIS to the posterior pole of the femoral nerve was statistically greater with participants in the sidelying position (mean[SD] = 35.7 [6.2] mm) than in the supine position (mean[SD] = 32.1 [7.3] mm, p < .001).

Discussion: Although more study is needed, these results suggest that patient positioning is one of several potential variables that should be considered in the optimization of patient safety/relative risk when performing trigger point dry needling.

Level of Evidence: Level 4 (Pre-Post Test)

KEYWORDS:

• Trigger point
• dry needle
• patient position
• risk
• safety
• iliacus

Acknowledgments

The authors would like to thank their employers, including Atrium Health, Myopain Seminars, NxtGen Institute of Physical Therapy, Evidence in Motion, Baylor University, South College, Novant Health, Hospital Provincial de Toledo, and MSK Masters for their support in the form of time allowances and work release in completion of this unfunded work. Thank you to Dan Steele, PT, DPT, of Carolinas Rehabilitation for modeling of the hip used for graphical illustration and video abstract. Thank you to Ashlee Hall and Ashley Baich for assistance in initial grammatical review and anatomical illustrations respectively. Finally, thank you to Michael Agnone, PT, OCS, ATC, LACT, CMTPT and Sherry Jones, PT for their vision in the creation of a position at Atrium Healthcare that balances clinical, teaching, and research interests of the primary author – without which this work would not have been possible. Correspondence concerning this article should be addressed to Andrew M. Ball, PT, DPT, PhD, OCS, DAC, CMTPT, CertMSKUS, Atrium Health, Carolinas Rehabilitation, Mountain Island Lake, 9908 Couloak Drive, Charlotte, NC. 28216. Email [email protected] or [email protected]

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data can be accessed here.

Additional information

Notes on contributors

Andrew M. Ball

Andrew M. Ball graduated from Ithaca College in 1995 with his MSPT, from Century University in 2002 with his PhD, from MGH Institute of Health Professions in 2005 with his DPT, and from the Carolinas Rehabilitation Orthopaedic Residency in 2011, where he subsequently served on faculty through 2017. He is an ABPTS-certified specialist in orthopedics. Certified in sport performance enhancement (PES), diagnostic musculoskeletal ultrasound (CertMSKUS), and dry needling (CMTPT), Dr. Ball serves as Lead Therapist of the Carolinas Rehabilitation - Mountain Island Lake clinic at Atrium Health, is Vice President of Quality and Performance for the NxtGen Institute for Physical Therapy, and is a Dry Needling Instructor for Myopain Seminars.

Michelle Finnegan

Michelle Finnegan Dr Finnegan is a full-time clinician specializing in orofacial pain at ProMove PT Pain Specialists and is a senior instructor for Myopain Seminars. She is a board-certified orthopedic certified specialist and cervical and tempormomandibular therapist. She is coeditor of the third edition of the Travell & Simons Trigger point book and a regular contributing coauthor for a quarterly review column for the Journal of Bodywork and Movement Therapies on myofascial pain literature. She also serves as a manuscript reviewer for several journals.

Shane Koppenhaver

Shane Koppenhaver received his Masters of Physical Therapy degree from the U.S. Army/Baylor University Graduate Program in 1998, and a PhD in Exercise Physiology from the University of Utah in 2009. He became board certified in Orthopedic Physical Therapy in 2001 and completed a fellowship in manual therapy through Regis University in 2009. Dr Koppenhaver has published approximately 60 manuscripts in peer-reviewed journals and received over $2,000,000 in grant funding for studies primarily concerning low back pain, spinal manipulation, dry needling, and the use of ultrasound imaging in the measurement of muscle function. His primary research interests concern mechanistic and clinical outcomes associated with manual therapy and dry needing, especially as they apply to clinical reasoning and management of patients with neuromusculoskeletal conditions.

Will Freres

Will Freres graduated from Northern Illinois University’s physical therapy program in 2010. He completed Carolinas Rehabilitation’s orthopedic physical therapy residency in 2012 and has been a faculty member for this program since 2014. In 2017 he completed fellowship education in manual and manipulative therapy. He holds two certifications in dry needling and has lab assisted for two continuing education providers specializing in dry needling. He is Director of the NxtGen Institute of Physical Therapy's Orthopedic Manual Therapy Fellowship Program, and currently sees patients at the Dowd YMCA clinic at Atrium Health in Charlotte, NC. i

Jan Dommerholt

Jan Dommerholt is a Dutch-trained physical therapist who holds a Master of Professional Studies degree with a concentration in biomechanical trauma and healthcare administration, and a Doctorate in Physical Therapy from the University of St. Augustine for Health Sciences. Currently, he is pursuing a Ph.D. degree at Aalborg University in Denmark. Dr Dommerholt was the first physical therapist to practice or teach dry needling in the Unites States, has taught many courses and lectured at conferences throughout the United States, Europe, South America, and the Middle East while maintaining an active clinical practice. He has edited four books on myofascial trigger points and manual physical therapy, authored nearly 60 book chapters and over 80 articles on myofascial pain, fibromyalgia, complex regional pain syndrome, and performing arts physical therapy. Dr Dommerholt is president/CEO of Myopain Seminars, Bethesda Physiocare®, and CEO of PhysioFitness.

Orlando Mayoral del Moral

Orlando Mayoral del Moral graduated as a PT from Valencia University, Spain, in 1987. He got his MSc in Castilla-La Mancha University, in Toledo, Spain, in 2006, and his PhD in Alcalá University (Madrid, Spain) in 2017. He works as a PT in Hospital Provincial (Toledo, Spain) and in ‘Orlando Mayoral’s clinic’ (Madrid, Spain); as academic director and professor in Seminarios Travell & Simons®; as a postgraduate professor in many universities in different countries; and as a researcher in several research groups. His activities are mostly focused in myofascial pain syndrome and in dry needling technique.

Carel Bron

Carel Bron graduated from Hanze University for Applied Sciences Groningen in 1979 and received his Manual Therapy education in Eindhoven (currently known as the SOMT University, Amersfoort) in1988. He was a researcher between 2002 and 2015 at the University Medical Centre Nijmegen and earned his PhD degree in 2011. He is cofounder of the Dutch myofascial pain seminars in Groningen and co-owner of a physical therapy practice where works as a manual physical therapist specialized in shoulder disorders. He is a researcher at the University Medical Centre Groningen.

Randy Moore

Randy Moore is a doctor of chiropractic who has devoted more than 2 decades of his career exclusively to musculoskeletal sonography. Registered by the American institute of ultrasound medicine (AIUM) in musculoskeletal and medical sonology, Dr Moor has published two books designed to be easy-to-understand and implement guides for the musculoskeletal sonologist.

Erin E. Ball

Erin E. Ball received her DPT from Duke University in 2003. She earned her lymphedema certification in 2005 and her COMT through MAPS/Maitland in 2010. Erin started her training in dry needling in 2011, earned her certification in 2012,and now serves as Lab Instructor for Myopain Seminars. She then became ABPTS board certified in Women’s Health Physical Therapy in 2016. Dr Ball currently serves as regional manager for Novant Health in Charlotte, NC.

Emily E. Gaffney

Emily E. Gaffney received her Doctorate in Physical Therapy from the Army-Baylor University Doctoral Program in Physical Therapy in August 2017. She is currently serving as an Active Duty officer for the US Army stationed in Fort Drum, NY. Certified in dry needling, Dr Gaffney currently practices as a staff physical therapist at the US Army Medical Department Activity’s Guthrie Ambulatory Health Care Clinic where she serves the active duty and dependent population of the 10th Mountain Division.