Table 1

Characteristics of included studies

Study, year (Reference)SettingParticipants, nPopulation descriptionPopulation characteristicsMethod of SDMD measurementSite(s) measuredFundingMethodological quality
Jutte et al 201228USA389College students.196 division 1 athletes (39 women, 157 men) and 193 recreationally active college athletes (85 women, 108 men). No underlying health conditions were reported.Mean of 3 skinfold measurements by callipersHalf the distance between the deltoid tubercle and the acromioclavicular jointNone describedNo concerns
Nakajima et al 202025Japan27Healthy volunteers during anatomy practice for medical students.11 female (mean age 22.3 years, mean BMI 21.7 kg/m2), 13 male (mean age 22.7 years, mean BMI 21.2 kg/m2)Ultrasound B-mode measurement made three times avoiding compression by the probe which was held at a 90° angle to the plane of examined sites3 finger breadths below the mid-acromion, and the intersection of a line dropping from the middle acromion and a line connecting the most superior point of the anterior and posterior axillary line.JSPS KAKENHI under Grant Number 18H03072No concerns
Nakajima et al 201726Japan30Healthy volunteers.15 female (mean age 21.8, mean BMI 19.3 kg/m2), 15 male (mean age 21.0 years, mean BMI 20.2 kg/m2)Mean of 3 measurements per site by callipers (divided by 2) and by ultrasound B-mode(1) The intersection between a perpendicular line drawn from the mid-acromion lateral border, and a line connecting the most superior point of the anterior and posterior axillary folds. (2) 1/3 of the distance from the mid-acromion lateral border to 1). (3) 1/2 the distance from the mid-acromion lateral border to 1), and 4) 2/3 the distance from the mid-acromion lateral border to 1).JSPS KAKENHI under Grant No 25 293 430No concerns
Sim et al 201427Korea156People with type 2 diabetes.Mean age 62.2 years; 46.2% female, mean BMI 24.09 kg/m2, 58.4% participants were overweight, 32.7% used insulin for blood sugar control, and 40% had experienced complications of diabetesUltrasoundLocations of upper arm insulin administration using an injection site chart developed in a previous study. Sites 1 and 2 appear to be over the deltoid around the most superior point of the anterior axillary fold.Partially supported by the Becton Dickinson and Company, but no potential conflict of interest relevant to this article was reported.Site chart unavailable, unable to confirm exact sites measured relative to anatomical landmarks nor distance between sites.
Cook et al 20067Australia256Convenience sample of ambulant patients aged 65 years and older stratified over 5 BMI groups, who had no underlying upper limb injury or neurological or muscular disease of the upper arm.122 female (mean age 71.3 years), 134 male (mean age 72.1 years). BMI <20 kg/m2 (18 participants), BMI 20–24.9 (67 participants), BMI 25–29.9 (87 participants), BMI 30–34.9 47 participants), BMI ≥35 (37 participants)Ultrasound linear array high frequency probeMidpoint between acromion and deltoid tubercle on both armsHunter Rural Division of General Practice partially funded the statistical analysis conducted
by Datapharm Australia		No concerns
Shankar et al 20148India200Convenience sample of attendants of patients coming to the radiology department at a medical college hospital.100 female (mean age 32.9 years, mean BMI 24.7 kg/m2), 100 male (mean age 34.8 years, mean BMI 23.7 kg/m2)Ultrasound measurements of both arms1/3 the distance of the acromion to the mid-point of the acromion to the lateral epicondyleNone reportedNo concerns
Li et al 2007 29Taiwan36Convenience sample of patients undergoing transradial catheterisation; 18 who had a clinically significant haematoma postprocedure, and 18 control patients who did not have significant haematoma postprocedure.18 haematoma group (mean age 69.5 years, mean BMI 23.6 kg/m2, 50% female), 18 control group (mean age 61.5 years, mean BMI 23.63 kg/m2, 55.6% female)Calliper measurement of skinfold in the right deltoidDeltoid muscle areaNone reportedNon random sampling
Lippert and Wall 200818USA150 (30 eligible)Retrospective review of 150 patients from a children’s hospital who had an MRI or CT of their normal deltoid muscle. Data for 30 of these were eligible for consideration in this review.30 aged 16–18 years (mean 16.5).MRI/CT5 cm distal from the acromion (roughly middle 1/3rd of muscle) at 90° angle to the skin, as per CDC recommendationNone reportedUnable to extrapolate demographics for participants of eligible age. Differences in CT/MRI measurements were not discussed nor a breakdown of proportion of scans of each type presented.
Poland et al 19979US220Healthcare workers presenting to an immunisation clinic for hepatitis B vaccination126 women (mean age 35.9 years, mean BMI 25.7 kg/m2), 94 men (mean age 33.9 years, mean BMI 25.8 kg/m2)Ultrasound and skinfold calliper measurements over the deltoid at the proposed injection site on the non-dominant arm3 finger breadths below the acromion process in the midline, and above the anterior axillary lineNone reportedNo concerns
Hobbins et al 201424 45UK28Opportunistic sample of patients prescribed epinephrine autoinjectors for a clinical history of anaphylaxis from a non-allergy specialist, on their attendance to a specialist allergy clinic.23 female, 5 male (mean age 49.0 years, mean BMI 29.5 kg/m2)Mean of three ultrasound measurements of the deltoid area on both armsDeltoid muscle areaNational Pollen and Aerobiology Research Unit at the University of Worcester, UKDeltoid IM injection site measured was protocolised but unable to clarify exact location.
Middleman et al 20103USA42Adolescents and young adults aged 14–24 years who weighted>90 kg (female) and >120 kg (male) who had never received a hepatitis B vaccination.40 female and 2 male, (mean age 20.7 years, mean BMI 40.4 kg/m2)Mean of 3 skinfold measurements of the deltoid on the non-dominant arm3 fingers below the acromionSAM/APA/CDC Adolescent Special Immunisation Projects Award 2001, Project 1 T71 MC00022-01 from the Maternal and Child Health BureauLimited male participants.

  • BMI, body mass index; CDC, Centers for Disease Control and Prevention; SAM/APA, Society for Adolescent Medicine / Ambulatory Pediatric Association.