An exploratory study was done on fourteen females to find the depth of the subcutaneous tissue and the length of needle required to reach the musculature. Gross body measurements were correlated with the internal measurements to develop criteria predicting the depth on other individuals. Review of the literature showed that most authorities recommend two to two and one-half inch needles, while available disposable needles range from one-half to one and one-half inches in length. A pilot study of measurements taken on postmortem subjects was reported as unsatisfactory. The electrocardiograph with coaxial needle electrode was demonstrated to be a very accurate tool for internal measurements on live subjects and was used to measure the subcutaneous tissue depth at four intramuscular injection sites: (1) deltoid, (2) gluteus maximus, (3) gluteus medius, and (4) lateral femoral. Pearson product-moment correlations and regression lines were computed for each of the variables. Data from the study were compared with two body measurement studies of 22,000 and 10,042 individuals respectively and the sample was found to be homogeneous with the population. Weight and girth were found to have the highest cor- relations with the depth of the subcutaneous tissue. Factors which may have influenced the findings were: (1) the sample was convenience rather than random, (2) the sample was small, (3) the lack of a wide range of subjects of varying sizes, and (4) the normal fear and hostility toward injections. The range of data was as follows: age, 19-48 years; weight, 104-172 pounds; height, 51-70.5 inches; deltoid girth 10.25-14.00 inches; hip girth, 34-43.75 inches; and mid-thigh girth, 16.25-24.25 inches. The average woman in the sample weighed 141.5 pounds, was 65.5 inches tall, and had a hip girth of 39.53 inches with 1.8 inches of subcutaneous tissue over both gluteal sites. The arms girth was 12.10 inches with 0.57 inch of subcutaneous tissue at the deltoid site, and the mid-thigh girth was 19.53 inches with sub- cutaneous tissue of 0.85 inch at the lateral femoral site. Scatter diagrams and regression lines were plotted on graphs. These provide a tool for predicting the depth of the subcutaneous tissue from the weight of the individual or from the respective girth of the specific site. The conclusions from this study are: (1) there is a greater amount of subcutaneous tissue lying above the muscle mass than has been assumed by many individuals and by the suppliers of equipment, (2) that many injections are not reaching the muscle mass and therefore are ineffective and troublesome, (3) there is a positive relationship between body size and the depth of the subcutaneous tissue, (4) it is possible to predict from the body size, the depth of the subcutaneous tissue, (5) the depth of the subcutaneous tissue over the gluteal areas usually exceeds 1.8 inches, (6) the depth of the subcutaneous tissue over the deltoid area usually exceeds 0.57 inch, (7) the depth of the subcutaneous tissue over the lateral femoral area usually exceeds 0.85 inch, and (8) needles of at least two and one-half inches in length are required to administer an injection in the gluteal regions on the "average" woman.
Albert E. Hirst
Year Degree Awarded
Date (Title Page)
Library of Congress/MESH Subject Headings
Injections, Intramuscular; Needles -- utilization; Nursing Care
Loma Linda University Libraries
This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.
Blumenshein, Olive Vaughan, "Needle Length Required for Intramuscular Injection in Women" (1966). Loma Linda University Electronic Theses, Dissertations & Projects. 662.
Loma Linda University Electronic Theses and Dissertations
Loma Linda University. Del E. Webb Memorial Library. University Archives