In our search of keywords, several studies highlighting chiropractic injuries were available, but there were very few that addressed gender differences when delivering the particular therapy. In the Macanuel et al. studies, for example, most references were to injuries sustained by students while receiving adjustments, and gender references were made only with respect to actual responses received by participants [18, 19]. As well, in studies by Sensted et al., injuries reported were those sustained when receiving versus delivering "spinal manipulative therapy" [21, 22].
In some studies of work-related musculoskeletal symptoms in other professional students, dental hygiene students reported that 60% experienced some pain, 46% reported upper extremity pain, 13% reported numbness, and 13% reported white or painful fingers in cold temperatures [7]. Reports from another study by Anton et al. included a high prevalence of neck pain (68.5%) and shoulder symptoms (60%) in dental hygiene students [23]. Bork et al. reported that the highest annual prevalence of musculoskeletal disorders in physical therapists was in the low back, upper back, and neck, and that lower incidences of injury occurred in the shoulders, elbows, hips and thighs, knees, ankles and feet. The study found that more female therapists than male therapists had reported spinal, wrist and hand symptoms [24].
It takes time and effort on the part of the novice to learn the sophisticated and complicated skills necessary to perform a range of chiropractic adjustive techniques [9, 11, 18, 19]. Not all students have the same levels of coordination, dexterity, or experience when learning psychomotor skills, and some may be more adept or physically developed [20]. Data gathered from this preliminary study indicated that students reported sustaining injuries in their attempts to deliver adjustments in both the classroom and clinical settings, and that gender differences existed relative to the anatomical areas of injuries and the adjustive techniques used at the time of injury occurrence.
This study's findings did not reproduce similar gender difference complaints as those found by Mior and Diakow. They reported a higher prevalence of thoracic spine pain and shoulder pain complaints among female chiropractors and more low back pain complaints among male practitioners [11].
In the study of physical therapist injuries, Nyland and Grimmer found that, of first year students, females reported a greater prevalence of low back pain. However, in succeeding years of study, they found that 1st and 4th year female students reported a greater preponderance of low back pain, where 2nd and 3rd year male students reported a greater preponderance of low back pain [16].
It was difficult to compare chiropractic gender difference findings to other health related fields due to the predominance of females in the roles of dental hygienist and nurse for example, versus the male majority population in the chiropractic profession.
Limitations of the study became evident as the project progressed. Since the surveys were retrospective in nature, students were required to recall and document the circumstances of injuries that may have occurred many months prior. If students were surveyed sooner, for example, after the completion of each technique course, there may have been more accuracy in their recall and responses.
Another limitation was that, although data was collected for participant height and weight, the association of injury sustained to body type was not a focus of this study. This demographic data could be a consideration for future studies.
A third limitation of the study was that the survey did not address the descriptive characteristics associated with the students' injuries, or the length of time the injuries remained. No data was collected with respect to the amount of time that had elapsed between delivery of the procedure and the onset of student symptoms. Areas addressing descriptors such as throbbing, aching, numbness, tingling, deep, sharp, etc., and injury duration could be added to future studies for better data collection.
During the time of the study, student enrollment was greater for males than for females and was reflected in the numbers and percentages of the participant responses. It was understood that the sample student group was representative of the general student population of those who were taking/had taken adjustive technique courses, and those who were active in the clinics. The problem with this pilot group was the small number of students who actually participated in it. In order to acquire more substantial information, subsequent studies are currently being developed to address a significantly larger population of participants.
When the survey was developed, there was no peer review or test/re-test performed due to time constraints. This proved to be another limitation of the study, and may have caused some confusion for the participants. If feedback on the survey's appropriateness had been obtained, the confusion may have been avoided. Although lacking in some areas, the same survey will be used in the later studies to determine whether the statistical data and the study's limitations are repeatable, and if they exhibit consistency on a larger scale.
Further investigation into the details of participant responses and additional analysis of the demographic data may reveal if a predisposition exists for certain individuals to sustain injury, and/or if a particular anatomical area could be involved. Once additional data is integrated, the relationship, if any, of individual characteristics to anatomical areas of injury, and the use of specific adjustive techniques can be determined. This associative data may also serve as a data base for the development and integration of injury-prevention measures into technique coursework.