ABSTRACT
Objectives
Current literature remains inconclusive regarding the best methodology to accurately palpate lumbar spinous processes (SP). Body painting (BP) uses markers to draw anatomical structures on the skin’s surface. While BP can be a useful tool for engaging learners, it is unknown whether it improves palpation accuracy. The purpose of this study was to investigate whether the addition of body painting to palpation education improves lumbar spinous process palpation accuracy in first-year Doctor of Physical Therapy (DPT) students.
Methods
Thirty-eight DPT students were randomized into a traditional palpation group and a body painting (BP) group. Each group received identical instruction on palpating the lumbar spine, with the BP group additionally drawing lumbar SPs on their laboratory partner with a marker. Students were then assessed on their ability to accurately palpate the L4 SP on randomly assigned subjects. Two Certified Registered Nurse Anesthetists (CRNAs) used ultrasound imaging to confirm the location of each student’s palpation. Palpation time was also recorded. The BP group also completed a survey on the learning experience.
Results
Forty-five percent of students were able to accurately palpate the L4 SP. There was no significant difference (p = 0.78) in palpation accuracy between the traditional and BP group, although students in the BP group were randomly assigned subjects with a significantly (p = 0.005) higher BMI. Ninety-five percent of students were able to palpate within one spinal level of the L4 SP. Students in the BP group reported that the BP activity facilitated learning and active participation. There was no significant difference in palpation time (p = 0.98) between groups. There was a fair correlation (r=-0.41) between palpation accuracy and subject BMI.
Discussion/Conclusion
While body painting was an enjoyable activity to incorporate into palpation laboratory, it is unclear whether it enhanced lumbar SP palpation accuracy in first-year DPT students.
KEYWORDS: Palpation, lumbar spinous process, body painting, physical therapy
Introduction
Palpation is a fundamental skill taught in Doctor of Physical Therapy (DPT) education. Spinous process palpation is an integral part of musculoskeletal spinal examination to identify potential areas of pain or dysfunction [1]. However, there remains a need for further training in the skill and application of palpation. Current literature is inconclusive regarding the best methodology to accurately palpate lumbar spinous processes (SP) [2]. Harlick et al. found that experienced physiotherapists could accurately palpate a randomly nominated lumbar SP 47% of the time [3]. The same study found that physiotherapists were within one level of a randomly nominated lumbar SP 72% of the time [3].
Body painting (BP) uses markers to draw anatomical structures on the skin’s surface to visualize landmark location, muscle attachments, nerve pathways, and joint orientations. This method is commonly used during palpation laboratory instruction to visualize the structures being taught. Medical students that participated in body-painting activities reported positive feedback due to the kinesthetic component, peer-to-peer interaction, and active participation [4]. A survey of 96 medical school students concluded that a body-painting activity facilitated self-active learning and was useful for a number of applications [5]. Palpation laboratory activities in physical therapy education may incorporate body-painting to help students visualize musculoskeletal structures, but it is unknown whether or not this enhances clinical palpation skills. The purpose of this study was to investigate whether the addition of body painting improves lumbar spinous process palpation accuracy in first-year DPT students. A secondary purpose of the study was to assess students’ body painting learning experience via survey.
Methods
Thirty-eight DPT students in their first semester were eligible to participate in the study, which took place within the cohort’s first clinical examination class. This study used a convenience sample, and all students were asymptomatic of low back pain. The Institutional Review Board at Samford University approved this study. All students in the cohort voluntarily consented to participate and were divided into two groups prior to the study using simple randomization via random.org. The students were unaware of their group assignment. The traditional group participated in a lecture-laboratory activity that utilized traditional palpation on partners without visual aids. The body painting group participated in the same lecture-laboratory activity but also used markers to draw structures while palpating. Five days after the teaching session, students from each group were assessed on their palpation accuracy using a randomly assigned partner from their cohort, designated as the subject. Students were unaware of any differences in teaching methods between groups. Lumbar spine palpation is the first palpation activity performed by the DPT students in the curriculum. Data collection took place approximately 1 month after students were enrolled in the DPT program.
Each group received separate instruction using the same 60-min lecture and laboratory activity. During the lecture, students were taught to palpate the lumbar spinous processes using a combination of techniques. Education on lumbar palpation took into consideration the radiographic level of the PSIS at S2 [6], the level of the palpated intercrestal line most commonly at L3–4 [7], using multiple methods to confirm location [8], and sacral rocking to find L5 [9]. Palpation was performed with the subject in prone in order to be consistent with the textbook [1] and previous literature [10,11]. During the laboratory activity, students were taught a step-by-step method of palpating the lumbar spine, starting at S2 and palpating cranially. Students were encouraged to confirm their location with the various palpation methods described above. The 1-h sessions were held on the same day in the classroom; the traditional group was taught first followed by the BP group. The order of teaching was randomized via random.org. The traditional group practiced palpation during the laboratory time with a partner, while faculty monitored and assisted students as necessary. In addition to palpating during the laboratory activity, the BP group also attempted to draw each PSIS and spinous process using markers as demonstrated by the faculty instructor. An example of the body painting activity can be found in Figure 1.
Figure 1.
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The primary outcome of interest was palpation accuracy. Previous studies have utilized radiographs [3,8] or MRI [9] to confirm lumbar SP palpation accuracy, however ultrasound imaging was used in this study as it was readily available. Ultrasound imaging has been found to be a reliable and valid tool for identifying lumbar spinous process levels [12,13]
The use of ultrasound in the assessment of lumbar spine levels (LSLs) has been demonstrated to be accurate and useful for multiple specialties. In anesthesia literature, validation of LSLs is key for avoidance of spinal cord injury during central neuraxial blocks. Ensuring that the block needle is inserted caudal to the conus medullaris decreases the likelihood of cord contact and injury. To this end, ultrasound has been studied to evaluate its reliability for accurately assessing LSLs. A study by Broadbent et al. is frequently cited noting that palpation is generally 29% accurate in identifying a specific spinous process (SP) [14]. Ultrasound imaging is recommended over palpation alone for spinal anesthesia due to the ability to identify LSL consistently with ultrasound [15]. Palpation inaccuracy has been reported to be both consistently higher [15,16] and lower [12] than the intended target SP. In contrast, the use of ultrasound to identify LSLs has a success rate between 68% and 71% [13,15,16]. In a more recent study comparing palpation versus ultrasound for identifying the L3 SP in prone, Mieritz and Kawchuk reported that palpation yielded a mean distance error of 26 mm, while ultrasound imaging had a mean distance error of 0 mm [12]. Utilizing radiologic imaging to confirm ultrasound assessments has provided insight into the accuracy that can be achieved when using this technology [13,15,16]. Additionally, Halpern noted that the accuracy of providers using ultrasound with little training is remarkably high with a short learning curve.
This study utilized ultrasound technology (LOGIQ e, GE Healthcare) and a curved probe to evaluate marked palpation landmarks. Longitudinal axis planes (sagittal view) of the spine were obtained beginning at the sacrum as seen in Figure 2.
Figure 2.
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From this point, the ultrasound was moved cephalad to identify the lumbosacral gap. Once this was identified, the L5, L4, and L3 spinous processes were located. After the L4 SP was confirmed on ultrasound, a comparison was made with the surface landmark as seen in Figure 3. Notation was made if the surface marker was cephalad to the probe’s center, at the same location as the probe’s center, or caudal to the probe’s center. Findings were then recorded.
Figure 3.
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Ultrasound assessment was performed by two trained Certified Registered Nurse Anesthetists (CRNAs) with a combined 31 years of ultrasound imaging experience. A third assessor measured the time it took each student to palpate the specified level as this was a secondary outcome of interest. All assessors were blinded to the students’ group assignments. All students were instructed to palpate the L4 spinal level to reduce variability. The primary investigator did not take part in the data collection as they randomly assigned the groups and performed the teaching intervention.
This study used both non-parametric (accuracy) and parametric data (age, height, weight, BMI, time). Palpation accuracy was recorded as a dichotomous ‘inaccurate’ or ‘accurate’. Inaccurate results were recorded as 0, while accurate results were recorded as 1 for statistical analysis. A Mann–Whitney U test was used to assess differences in palpation accuracy between groups. Baseline age, height, weight, and BMI were analyzed with an independent t-test. Age, height, weight, and student BMI were all normally distributed as calculated by D’Agostino’s Normality test. Correlations between accuracy and BMI were determined using a point-biserial correlation coefficient. Differences in palpation time between groups were determined using a paired t-test. A Spearman-rank correlation was used to determine any correlation between accuracy and time. Alpha was set to 0.05 for all statistics. There were no dropouts, and data were analyzed from each student.
Lastly, students in the BP group completed a survey following the palpation assessment, but prior to information on their accuracy. Students were asked to rank their agreement to various statements using a 5-point Likert scale. The statements included the impact body painting (drawing) had on their learning experience. The survey statements were used in a previous study on the role of body painting in the active learning of medical students [5].
Results
The descriptive statistics of each group can be found in Table 1. There were no significant differences (p > 0.05) between groups at baseline in age, sex, height, or student BMI.
Table 1.
Participant characteristics.
| Traditional (n=19) | Body Painting (n=19) | Difference (p-value) | |
|---|---|---|---|
| Age | 22.2 ± 0.99 | 22.6 ±1.9 | 0.49 |
| Sex | M=5, F=14 | M=7, F=12 | 0.49 |
| Height (in) | 67.4 ± 3.4 | 67.8 ± 4.7 | 0.78 |
| Weight (lbs.) | 157.7 ± 27.2 | 162.6 ± 41.6 | 0.67 |
| Student BMI | 24.2 ± 2.2 | 24.6 ± 4.2 | 0.75 |
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Values presented as mean ± standard deviation.
Age, Height, Weight, and BMI analyzed with a t-test. Sex analyzed with a chi-squared test.
Seventeen out of 38 students (45%) correctly palpated the L4 spinous process. The frequency that each spinous process was palpated can be found in Table 2. There was no significant difference (p = 0.78) in palpation accuracy between the traditional (47%) and BP (42%) groups. Thirty-six of 38 students (95%) palpated within one spinal level of L4, while only 2 students palpated the S1 spinous process. There was no significant difference (p = 0.98) in the average time it took to palpate between the traditional (39.5 s) and BP groups (39.3 s).
Table 2.
Frequency of palpation results by SP.
| Spinous Process | Traditional Group | Body Painting Group |
|---|---|---|
| L3 | 5 | 5 |
| L4 | 9 | 8 |
| L5 | 4 | 5 |
| S1 | 1 | 1 |
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p>0.05 for differences in frequency of SP palpation.
Each student performed their palpation assessment on a randomly assigned subject regardless of the initial group assignment. Students in the BP group were randomly assigned subjects with a significantly (p = 0.005) higher BMI than the traditional group. Furthermore, the BP groups’ subjects had a mean BMI of 25.8 ± 3.6, which qualifies as overweight. The traditional group’s subjects had a mean BMI of 23.0 ± 2.3. Significant (p = 0.01) point-biserial correlation between student palpation accuracy and subject’s BMI was found (r = −0.41), meaning an increase in the subject’s BMI fairly correlated with a decrease in the student’s palpation accuracy during the assessment.
When excluding subjects with a BMI greater than 25, the BP group had a palpation accuracy of 60% (6 out of 10 accurate) compared to 54% in the traditional group (7 out of 13 accurate). However, this difference was not statistically significant (p = 0.80).
The statements from the BP survey, along with the results of the survey, can be found in Figure 4. Students largely agreed that body painting facilitated their learning, was interesting and fun, facilitated their active participation, and gave a sense of each landmark’s location. There were no students in the BP group that selected ‘strongly disagreed’ or ‘somewhat disagree’ for any survey statements.
Figure 4.
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Discussion
First-semester DPT students were able to palpate a randomly nominated lumbar SP with 45% accuracy. Additionally, 95% of students were within one spinal level. This level of success is on par with that of experienced manipulative physiotherapists (47%) as reported by Harlick et al. [3] Additionally, the accuracy of a physician resident training in Neuromusculoskeletal Medicine was 51% using multiple bony landmarks [8]. Palpation accuracy of L4 SP performed by 14 doctors of chiropractic was as 35.7% when using the Intercrestal (Tuffier’s) line in isolation [9].
Palpation reliability and accuracy improve with practice [8,17,18], and it is believed that this frequency of palpation accuracy will increase as students practice lumbar SP palpation throughout the curriculum.
The findings from the body painting survey are consistent with those found during body painting activities in medical school students [5]. Body painting while palpating facilitated learning, provided a fun and interesting activity, enhanced participation, and provided a sense of each landmarks’ location. While the educational experience was positive, the drawing activity did not result in a significant difference in palpation accuracy when compared to traditional palpation without the use of visual aids. This may be due to the fact that palpation is a psychomotor skill, and both groups received psychomotor training. Additionally, a survey on the educational experience for the traditional group was not given.
Limitations
There are several limitations to the study that may have influenced the results. First, using ultrasound imaging to confirm palpation location may impact the validity of the study. To mitigate this limitation, two CRNAs with significant ultrasound experience were recruited for the assessment. The assessors were in agreement with each patient as to the level of the L4 spinous process.
Additionally, the small sample size (n = 38) is not enough to draw definitive conclusions on palpation accuracy of first-year PT students in general. Additionally, the mean BMI of the BP group’s palpated subjects was significantly higher than that of the traditional group despite randomly assigning subjects for each group. This may have resulted in poorer palpation accuracy and the potential for a type II error. A higher BMI has been shown to diminish palpation accuracy in the cervical [19], thoracic [20], and lumbar spinal regions [8,14,16,21,22]. Of note, the L4 SP was not identified successfully in the four subjects with BMI > 29, all of whom were palpated by the BP group.
The choice of using L4 as the target SP may also have been a limitation. There are many landmarks (PSIS, iliac crest) that may have assisted subjects in identifying L4. Future studies may potentially use a spinous process with less associated landmarks to isolate the effectiveness of body painting. Additionally, it is unclear if placing subjects in prone compared to other viable positions may have influenced the results of the study.
Previous studies have described both lumbarization of the first sacral vertebrae and sacralization of the fifth lumbar vertebra [23]. Lumbarization can be found in 5.5% of the population, while sacralization has been observed in 7.5% of spines [23]. These variations were not visualized by the CRNAs performing the ultrasound assessment; however, variations might have been present in some subjects and had undue influence on palpation accuracy.
Lastly, students were instructed to not discuss the palpation assessment with each other; however, it is possible that students that were assessed later in the day knew they would be palpating L4, giving them a possible advantage. Additionally, students were not dissuaded from practicing palpation before data collection. Students may have practiced to varied amounts.
Conclusion
This study assessed the ability of novice DPT students to palpate the L4 spinous process with two different teaching methods. Students were able to palpate the L4 SP with 45% accuracy when compared with ultrasound imaging. Ninety-five percent of students were able to accurately palpate within one spinal level. It is unclear whether the visual aid provided by body painting has an impact on palpation accuracy. A higher BMI seemed to influence palpation accuracy, which is consistent with previous studies. The use of body painting may enrich the learner’s experience and additionally may improve accuracy when subjects have BMI > 25. This is the first study investigating the role of body painting on palpation accuracy. Future instruction on palpating lumbar SPs should emphasize the use of multiple bony landmarks performed during multiple practice sessions. Future studies need to investigate the influence of body painting on palpation accuracy in other body regions while also controlling for BMI.
Consent for publication
We consent to have this work published. This work is not submitted elsewhere, and the work is original to the authors.
Biographies
William M. Scogin, PT, DPT, ScD, is an Assistant Professor of Physical Therapy at Samford University in Birmingham, AL. He is a Board-Certified Orthopaedic Clinical Specialist by the American Board of Physical Therapy Specialists, as well as a Certified Orthopedic Manual Therapist by the International Academy of Orthopedic Medicine – US. His research areas include palpation, chronic pain, and the clinical implications of anatomical variations.
David Sanford, DNP, CRNA, EMT-P is an adjunct professor in the Moffett and Sanders School of Nursing, Department of Nurse Anesthesia at Samford University. In the clinical role, he is chief of operations for nurse anesthesia at Ascension St Vincent's Hosptial in Birmingham, AL.
Mary beth Greenway, DNP, CRNA is on faculty at Samford University in the Moffett and Sanders School of Nursing's Nurse Anesthesia Department. She teaches Obstetric Anesthesia, Advanced Health Assessment, and Nursing Education. Her areas of interest include anesthesia in developing countries and obstetric anesthesia.
Maria Ledbetter, DNAP, CRNA, is an Assistant Professor of Nurse Anesthesia at Samford University in Birmingham, Alabama. She has been a practicing Certified Registered Nurse Anesthetist for 25 years. Her clinical practice is as an Obstetric CRNA in Nashville, TN. Her expertise is in neuraxial anesthesia/analgesia, and her research interests are postdural puncture headache prevention and treatment and non-opioid analgesic adjuvants in labor analgesia.
Nicholas B. Washmuth, PT, DPT is an Associate Professor of Physical Therapy at Samford University. He is a Board-Certified Orthopaedic Clinical Specialist by the American Board of Physical Therapy Specialist. He teaches in the area of orthopedic physical therapy. His research areas include swearing, erectile dysfunction, anatomy, and biomechanics.
Funding Statement
The author(s) reported that there is no funding associated with the work featured in this article.
Disclosure statement
No potential conflict of interest was reported by the author(s).
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