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E-books by Robert D. Jansen, Ph.D.

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Curriculum Vita RDJ

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The Psychology of Smoking Why do humans smoke tobacco and love it so? Some good answers from various psychological perspectives. Includes Freudian, behavioral, cognitive, etc. plus psychological tips for quitting. 

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In the early 1990's I served as executive director of a research consortium of chiropractic colleges. Chiropractors had done little scientific research at that time, and part of my job was introducing the concepts of scientific method to clinical practitioners, many of whom had little formal training in science. One of the best ways to reach these chiropractors was by writing a column in a widely read trade journal called Dynamic Chiropractic. They are still available on the web in the archives of this publication.  I have listed below those columns which, because they attempt to introduce the basic issues of scientific method, may be of more than passing historical interest. Use the "Printer friendly" toggle if you want to print them out for your own use.

Transcending Testimonials and Impossible Chickens
Rooms Without Windows
Pseudoscientific Seminars
Improving the Case
The Crutches of Those Who Were Not Cured
Hypnotizing Trees?
Putting Confidence Where it Can't Be Lost
Taking Responsibility
The Protection of Research Subjects
Measuring Outcomes Instead of Incomes
Adjusting To Change
Abstracts of articles from a Medline search conducted on June 27, 2005, for author: R.D.Jansen (see also CV)

1: Altern Ther Health Med. 1999 Jan;5(1):56-62.

Use of complementary healthcare practices among chiropractors in the United
States: a survey.

Hawk C, Byrd L, Jansen RD, Long CR.

Palmer Center for Chiropractic Research, Palmer College of Chiropractic,
Davenport, Iowa, Davenport 52803, USA.

CONTEXT: Although chiropractic is the most commonly used complementary
healthcare practice, chiropractors have not been surveyed in depth about their
attitudes toward and practice of complementary and alternative therapies apart
from spinal manipulation. OBJECTIVES: To examine attitudes among US
chiropractors on the role of their profession in complementary healthcare and to
gather data on the types of complementary healthcare practices chiropractors
use. DESIGN: Descriptive, cross-sectional study using a mail-in survey. SETTING:
United States. PARTICIPANTS: Random sample of US chiropractors stratified by zip
code region. RESULTS: A total of 563 surveys were completed, for a response rate
of 30%. Respondents were almost equally divided on their responses to the
question "Do you feel that chiropractic should at the present time be termed
'complementary'?" Although many respondents (68%) believed that chiropractic was
viewed as a therapeutic modality, more (82%) believed that it should be viewed
as a complete system. The therapies most commonly used by respondents in their
practice were acupressure (72%), massage (72%), mineral supplements (63%), and
herbs (56%). CONCLUSION: The disparity between the established view of
chiropractic as synonymous with spinal manipulation and the profession's view of
chiropractic as a complete system indicates a need for better interprofessional

PMID: 9893316 [PubMed - indexed for MEDLINE]

2: J Manipulative Physiol Ther. 1998 Jul-Aug;21(6):429-32; author reply 434.

Comment on:
J Manipulative Physiol Ther. 1997 Nov-Dec;20(9):602-6.

The effects of spinal manipulation on the intensity of emotional arousal in
phobic subjects exposed to threat stimulus: a randomized, controlled,
double-blind clinical trial.

Jansen RD.

Publication Types:

PMID: 9726076 [PubMed - indexed for MEDLINE]

3: J Manipulative Physiol Ther. 1998 Jan;21(1):19-26.

Measurement of soft tissue strain in response to consecutively increased
compressive and distractive loads on a friction-based test bed.

Jansen RD, Cooperstein R.

Palmer Center for Chiropractic Research, Palmer College of Chiropractic West,
San Jose, CA 95134, USA.

PURPOSE: To abstract the essential elements of chiropractic prone leg checking
and subject them to controlled, experimental parametric testing. DESIGN:
Controlled, objective, repeated-measure analysis of the dynamic response of leg
positions to distractive and compressive loading conditions. SETTING: Research
laboratory in a chiropractic college. PARTICIPANTS: Twenty-five compression and
30 distraction subjects, most of whom were male, asymptomatic chiropractic
students. INTERVENTION: The subjects were lowered to the prone position on a
table optimized to detect dynamic leg positions, with separate sliding segments
supporting each leg. A trial consisted of a 2-min control run, followed by two
2-min experimental runs in which compressive or distractive loads were applied
incrementally to the table-leg segments. MAIN OUTCOME MEASURE: An optoelectric
system measured real-time absolute and relative leg positions. RESULTS: Right
legs showed a greater average response than left legs under both distractive and
compressive loads, and tended to respond more proportionately to incremental
load increases. The average response to compression exceeded the response to
distraction. Both legs showed a greater average response in the second half of
the trials. Correlation of weights with responses was about four times greater
in traction than compression. CONCLUSION: The functional short leg is confirmed
as a stable clinical reality, a multitrial mean of unloaded leg positional
differences. The prone leg check may be a loading procedure, albeit unmeasured,
that detects non-weight-bearing, functional asymmetry in loading responses.
These probably reflect differences in left-right muscle tone, joint flexibility
and tissue stiffness. The relatively nonmonotonic, nonlinear quality of left leg
responses is consistent with asymmetric neurological responses.

Publication Types:
Clinical Trial

PMID: 9467097 [PubMed - indexed for MEDLINE]

4: J Manipulative Physiol Ther. 1990 Sep;13(7):370-7.

Analysis of dynamic standing foot force patterns in a normal male subject by
characterization of microvector weight transfer sequences.

Nansel DD, Jansen RD, Szlazak MJ.

Research Department, Palmer College Chiropractic-West, Sunnyvale, CA 94087.

Previous foot forceplate analyses in our laboratory have shown that postural
sway in a normal male subject induces net weight transfers (microvectors) which
have preferred directionalities, and that eye closure is characterized by
increases in both the occurrence and magnitudes of these preferred microvectors.
The same data generated from 8 x 8 blocks of eyes-open and eyes-closed trials
were reanalyzed to examine microvector temporal sequences (i.e., macrovectors).
Macrovectors were defined by the number of successive microvectors occurring
along the same general direction, (anterior, posterior, right or left). Results
suggest that with eye-closure, proprioceptive systems are unable to maintain
lateral sway deviations within eyes-open limits. This instability increases
lateral macrovector durations while only marginally affecting sagittal
macrovector durations.

PMID: 2212882 [PubMed - indexed for MEDLINE]

5: J Manipulative Physiol Ther. 1990 Sep;13(7):361-9.

Power spectral and microvector frequency analysis of dynamic standing foot force
patterns in a normal male subject.

Jansen RD, Nansel DD, Szlazak MJ.

Research Department, Palmer College Chiropractic-West, Sunnyvale, CA 94087.

Power spectral and microvector frequency analyses of dynamic standing foot force
patterns in a normal male subject were performed using a multiple-trial
experimental protocol. Power spectral analysis of eight eyes-open vs.
eyes-closed 50-sec trials revealed significant power increases in the 0.14 to
0.66 Hz range with eye closure, which were repeatable in trials performed on the
same subject 2 wk later. Since power spectral differences are difficult to
interpret biomechanically, a (micro)vector analysis of 1/20 sec changes in
proportional weight transfer was employed. This methodology was able to reveal
that foot force weight transfer exhibited a distinct preferred directionality,
and that the eyes-closed condition was characterized by significant increases in
both the occurrence and average magnitudes of these preferred microvectors.

PMID: 2212881 [PubMed - indexed for MEDLINE]

6: J Manipulative Physiol Ther. 1990 Jun;13(5):243-6.

Normal paraspinal tissue compliance: the reliability of a new clinical and
experimental instrument.

Jansen RD, Nansel DD, Slosberg M.

Research Department, Palmer College of Chiropractic-West, Sunnyvale, CA 94087.

Test-retest reliability of a hand-held tissue compliance meter was evaluated in
20 normal subjects at four paraspinal locations to determine possible effects of
probe response or other sources of variability on measurements taken 10 min
later at exactly the same location. If tissue compliance, as measured by this
instrument, is to be used in a pre-post context to evaluate treatment effects,
caution is urged, since 26% of the sites were significantly (+/- 1.96 SD)
different on 10 min retest though subjects remained supine and without
intervention. In addition, since 85% of these normal subjects displayed at least
one paraspinal compliance asymmetry large enough to qualify as pathological by
Fischer's criteria, revision of these criteria may be appropriate, at least for
these paraspinal locations.

PMID: 2376718 [PubMed - indexed for MEDLINE]

7: J Manipulative Physiol Ther. 1989 Dec;12(6):428-33.

Comment in:
J Manipulative Physiol Ther. 1990 Jul-Aug;13(6):346-8.
J Manipulative Physiol Ther. 1991 Jan;14(1):85-90.

Interexaminer concordance in detecting joint-play asymmetries in the cervical
spines of otherwise asymptomatic subjects.

Nansel DD, Peneff AL, Jansen RD, Cooperstein R.

Department of Physiology/Pathology, Palmer College of Chiropractic-West,
Sunnyvale, CA 94087.

Interexaminer concordance for motion-based palpation of the middle and lower
cervical spine was investigated. The palpatory task consisted of determining
whether end-range joint resistance on lateral flexion was greater on one side of
a given cervical segment when compared to that of the contralateral joint.
Palpators also were asked to indicate the relative magnitude of the asymmetry,
when detected. All experiments were carried out using reasonably healthy,
pain-free, chiropractic college students. Three series of experiments involving
two pairs of practitioners and a total of 270 subjects were carried out.
Interexaminer agreement rates with respect to the side of greatest fixation were
not found to be significantly different from those expected by chance alone.
Furthermore, this was the case regardless of whether palpators had rated the
magnitude of the asymmetry as being slight, moderate or severe. These poor
agreement rates did not appear to be due to significant interexaminer
differences with respect to the distributions of right vs. left calls, to a
preponderance of agreements occurring more on one side over the other, or to
differences with respect to the distribution of severity ratings. More
importantly, there appeared to be no consistent relationships between the degree
of severity indicated by the first examiner and that indicated by the second,
nor were there any significant correlations between right vs. left agreement
rates obtained for various combinations of severity ratings.(ABSTRACT TRUNCATED

PMID: 2628521 [PubMed - indexed for MEDLINE]

8: J Manipulative Physiol Ther. 1988 Oct;11(5):355-65.

Diagnostic illusions: the reliability of random chance.

Jansen RD, Nansel DD.

Life Chiropractic College-West, San Lorenzo, CA 94580.

A "Monte Carlo" experiment was performed in order to determine chance
concordance rates for multiple test scenarios often encountered in chiropractic
diagnosis. The Monte Carlo simulation took into account the following variables:
the number of tests involved in the diagnosis; the number of vertebral segments
implicated by each test; the proportion of tests in agreement relative to the
number of tests performed; and the segmental margin of error accepted. Random
data for up to five diagnostic tests performed on 500 "patients" were computer
generated and a wide variety of test scenarios analyzed. One typical analysis
asked: if four diagnostic tests are performed on each patient, each test
implicating on average three vertebral segments, and a plus or minus one segment
error margin is accepted, what are the chance odds that any three out of the
four tests will implicate the same vertebral segment? The answer, determined by
simply counting how often this happened in the 500 "patients," was 89%. Many
test scenarios yielded chance levels much higher than might have been expected.
High probability situations as well as those test criteria yielding relatively
low chance concordance rates are identified.

PMID: 3235923 [PubMed - indexed for MEDLINE]

9: J Manipulative Physiol Ther. 1988 Aug;11(4):267-72.

Comment in:
J Manipulative Physiol Ther. 1989 Oct;12(5):402-4.

Concordance between galvanic skin response and spinal palpation findings in
pain-free males.

Nansel DD, Jansen RD.

Life Chiropractic College-West, San Lorenzo, CA 94580.

The concordance between areas of paraspinal low resistance, i.e., galvanic skin
response (GSR) and positive palpatory findings in pain-free male subjects was
investigated. The concordance between vertebral segments implicated by GSR and
by palpation was not found to be significantly different from chance concordance
as determined by a t-test comparison of experimental results to randomly
generated simulations, and by the application of Cohen's Kappa index of
concordance to experimental data. This was true even when the locations of low
resistance areas along the dorsal trunk were compared to only those vertebral
palpatory findings rated as "severe." When test-retest reliability of GSR was
examined, only 27% of vertebral segments implicated by GSR on initial
examination were also implicated in the same subjects 4 h later. It was noted
that low resistance areas detected by GSR were always punctate in nature and
appeared to correspond well to known acupuncture loci. Further investigation
revealed that, indeed, the GSR unit was not only effective in locating those
acupuncture points that happened to be in a state of lowered resistance at the
time but was also able, within about 5 sec, to decrease the resistance of any
particular point not already in its lowest state of resistance to a level
sufficient to generate a positive and persistent GSR reading where none had been
detected previously. It is suggested that GSR may not be a reliable predictor of
the location of vertebral pathology, at least as assessed by palpation in
pain-free subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

PMID: 3171414 [PubMed - indexed for MEDLINE]

10: Perception. 1982;11(5):535-40.

Attentional alterations of slant-specific interference between line segments in
eccentric vision.

Jansen RD, Blum GS, Loomis JM.

Slant-specific interference between line segments in eccentric vision was
altered by attentional methods in hypnotically susceptible observers. These
methods included negative and positive posthypnotic hallucination of the
inducing elements of the array, and nonhypnotic instruction to actively ignore
the elements. Contributions to the experimental effects apparently derived in
part from intrinsic inhibitory or facilitatory skill in the individual observer,
sharpened by hypnotic training in hallucinations. Control observers with low and
with high hypnotic susceptibility were not able to alter significantly the
interference effect when attempting to simulate the hallucination conditions.
The results seemingly link these attentional alterations to an early cortical
stage of visual processing.

PMID: 7186108 [PubMed - indexed for MEDLINE]