J Manipulative Physiol Ther 2006 (Jan); 29 (1): 51 ~ FULL TEXT
Joseph M. Evans, PhD, Daniel L. Collins, DC, Reed H. Grundy, BSEE
Sense Technology, Inc.,
3251 Old Frankstown Rd,
Pittsburgh, PA 15239
OBJECTIVE: To investigate patient response to multiple impulse therapy provided by the PulStarFRAS (Sense Technology, Inc, Murrysville, Pa) for a variety of musculoskeletal symptoms encountered in clinical practice.
METHODS: A retrospective analysis of patient files was used to determine symptomatic improvement over the course of treatment. The multiple impulse therapy was supplemented, at the discretion of the practitioner, with manual adjustments. The manual adjustments consisted of high-velocity low-amplitude and drop table, and represented fewer than 5% of the adjustments. Therapy was provided by a single practitioner in a private clinic setting.
RESULTS: Patients expressed improvement in symptoms after the first visit (average improvement in subjective pain rating scale of 41%). Patient symptoms improved between the first and second visits for 70% of patients (average improvement in subjective pain scale for all patients was 58%). The majority of patients achieved complete resolution of symptoms between the third and fourth visits. Maximum benefit for patients across all symptoms required an average of 4.2 visits. The half-life for response to multiple impulse therapy for all symptoms was 17 to 26 days. The half-life for response to multiple impulse therapy using the PulStarFRAS for low back pain was 9 to 16 days.
CONCLUSIONS: The results of this study suggest the further study of multiple impulse therapy provided by the PulStarFRAS as a means of resolving musculoskeletal complaints.
From the Full-Text Article:
The results of this study suggest that multiple impulse therapy delivered with the PulStarFRAS provided effective treatment for the 2 major conditions observed in this specific patient population: low back pain and neck pain. Follow-up of the patients who “dropped out” of the treatment program revealed that 4 of the dropouts did so because their pain level approached 0 after their last visit. Of the remainder, 3 stopped coming because they felt that the treatment did not help, 3 moved and could not be contacted, and 1 was referred out.
The patients in the study reported perceiving an immediate positive benefit after the first visit across all symptoms and that benefit increased (on average) between the first and second visit without additional treatment. A small number of visits were required to achieve maximum benefit across all symptoms. The average number of visits required to achieve 100% relief for those patients who continued therapy until they achieved a pain-free state was 3. When all patients in this group are included in the calculation, the average number of visits required to reach “maximum benefit” increased to 4.2. Maximum benefit was defined as the subjective ranking of pain made by each patient on his or her last visit. These results compare favorably with Cox flexion distraction (19 visits and 43 days to “maximum benefit”) and diversified (50% of patients reported that they had “improved” at the fourth visit and within 2 weeks). [4, 13]
Fig 3, Fig 4 compare the rate of patient response to physical therapy,  osteopathic manipulation,  and multiple impulse therapy performed with the PulStarFRAS. Physical therapy is defined in van den Hoogen et al as  “… combinations of exercise therapy and modalities such as heat, cold, and massage, and advice on daily behavior.” As can be seen, the Kaplan-Meier analyses of the results obtained with the PulStarFRAS compare favorably to osteopathic manipulation and physical therapy for the patient complaint of low back pain. [10, 14] It should be noted that the Kaplan-Meier results of van den Hoogen et al  were based on data obtained through the use of patient questionnaires and not through a face to face encounter. It is hypothesized that the responses might reflect a better outcome if the data were obtained directly by the clinician as the patient might wish to please the clinician (van den Hoogen, personal communication).
Comparison of these results to recent studies where the results are presented as a graph of 3 points is problematic. However, such a comparison using the simple exponential model as an approximation has been attempted by Evans. 
As this was a pragmatic retrospective study, the number of days between treatments was not controlled as part of the research design. Because the time between visits was not controlled, these results are likely to mirror common clinical practice more closely than results obtained in studies that control visit frequency. In this study, the clinician determined the time between patient visits on the basis of the apparent severity of the patient's complaint and on the capacity of the clinic. Following common practice, the patient is referred to the appointment desk for assignment to an open treatment slot as close as possible to the time for the return visit specified by the clinician. It is possible, indeed likely, that the number of days between treatments affects the rate of response to the treatment. No investigation of the treatment of musculoskeletal complaints has identified an optimal treatment frequency or suggested a procedure for developing a means of scheduling patients that will result in a maximum response to the treatment.
Rates of recovery were not found to be dependent on the length of time between the onset of the complaint and the first patient visit. Some studies find that chronic conditions respond more slowly to therapy than acute conditions. [16, 17] However, this finding is not universal. [18, 19] Again, the study of van den Hoogen et al  may be helpful. Fig 5 is a plot of the results of that study showing the response rates of untreated patients with acute, subacute, and chronic low back pain. For comparison, the responses of patients treated with multiple impulse therapy are also shown. Examination of this graph reveals that the response rate of patients treated with multiple impulse therapy is greater than the response rates of patients in the van den Hoogen study. That is, even patients with acute symptoms respond more slowly than patients treated with multiple impulse therapy. One interpretation of this observation is that multiple impulse therapy provided with the PulStarFRAS overpowers the effects of condition (acute, subacute, chronic) because the response of patients is much faster than the “untreated” response.
These observations lead to the hypothesis that methods of musculoskeletal therapy that exceed the rate of the natural healing response of the musculoskeletal system will not show differences in patient response related to the duration of symptoms before treatment. Or the corollary hypothesis that methods of therapy that are associated with differences in the response rate due to the duration of symptoms before treatment are unlikely to have exceeded the natural response rate of the musculoskeletal system.
Limitations of the study include the following: the clinician supplemented the multiple impulse therapy with manual adjustments; the number of patients  included in the study was small; the study was conducted at a single clinic; only 1 clinician provided the treatment; and the study used a retrospective, nonexperimental design. Before these results may be extended to the general patient population, additional studies are required that include larger patient samples, multiple clinicians, and clinics, and improved research designs to include randomized controlled trials.
The results of this study support continued study of multiple impulse therapy provided by the PulStarFRAS as a means of treating musculoskeletal symptoms.