Associations between demographics and clinical ideology, beliefs, and practice patterns: a secondary analysis of a survey of randomly sampled United States chiropractors.

BACKGROUND: The chiropractic profession in the United States (US) has a long history of intra-professional discourse surrounding ideology and beliefs. Large-scale efforts have evaluated 3 distinctive subgroups of US chiropractors focused on these areas of practice: spine/neuromusculoskeletal, primary care, and vertebral subluxation. To our knowledge, there have not been any prior studies exploring the factors associated with these ideology and belief characteristics of these subgroups. The purpose of this study was to explore, describe, and characterize the association of US chiropractors' ideology, beliefs, and practice patterns with: 1) chiropractic degree program of graduation, 2) years since completion of chiropractic degree, and 3) US geographic region of primary practice. METHODS: This was a secondary analysis of a cross-sectional survey of a random sample of US licensed chiropractors (n = 8975). A 10% random sample was extracted from each of the 50 states and District of Columbia chiropractic regulatory board lists. The survey was conducted between March 2018-January 2020. The survey instrument consisted of 7 items that were developed to elicit these differentiating ideologies, beliefs, and practice patterns: 1) clinical examination/assessment, 2) health conditions treated, 3) role of chiropractors in the healthcare system, 4) the impact of chiropractic adjustments [spinal manipulation] in treating patients with cancer, 5) vaccination attitudes, 6) detection of subluxation on x-ray, and 7) x-ray utilization rates. Multinomial regression was used to analyze associations between these 7 ideology and practice characteristic items from the survey (dependent variables) and the 3 demographic items listed above (independent variables). RESULTS: Data from 3538 respondents (74.6% male) were collected with an overall response rate of 39.4%. Patterns of responses to the 7 survey items for ideologies, beliefs, and practice characteristics were significantly different based on chiropractic degree program of graduation, years since completion of chiropractic degree, and geographic region of primary practice. CONCLUSIONS: Among US chiropractors, chiropractic program of graduation, years since completion of chiropractic degree, and geographic region of primary practice are associated with variations in clinical ideology, beliefs, and practice patterns. The wide variation and inconsistent beliefs of US chiropractors could result in public confusion and impede interprofessional integration.

Evaluation of United States chiropractic professional subgroups: a survey of randomly sampled chiropractors.

BACKGROUND: Professional subgroups are common and may play a role in aiding professional maturity or impeding professional legitimization. The chiropractic profession in the United States has a long history of diverse intra-professional subgroups with varying ideologies and practice styles. To our knowledge, large-scale quantification of chiropractic professional subgroups in the United States has not been conducted. The purpose of this study was to quantify and describe the clinical practice beliefs and behaviors associated with United States chiropractic subgroups. METHODS: A 10% random sample of United States licensed chiropractors (n = 8975) was selected from all 50 state regulatory board lists and invited to participate in a survey. The survey consisted of a 7-item questionnaire; 6 items were associated with chiropractic ideological and practice characteristics and 1 item was related to the self-identified role of chiropractic in the healthcare system which was utilized as the dependent variable to identify chiropractic subgroups. Multinomial logistic regression with predictive margins was used to analyze which responses to the 6 ideology and practice characteristic items were predictive of chiropractic subgroups. RESULTS: A total of 3538 responses were collected (39.4% response rate). Respondents self-identified into three distinct subgroups based on the perceived role of the chiropractic profession in the greater healthcare system: 56.8% were spine/neuromusculoskeletal focused; 22.0% were primary care focused; and 21.2% were vertebral subluxation focused. Patterns of responses to the 6 ideologies and practice characteristic items were substantially different across the three professional subgroups. CONCLUSIONS: Respondents self-identified into one of three distinct intra-professional subgroups. These subgroups can be differentiated along themes related to clinical practice beliefs and behaviors.

Description of the case mix experienced by chiropractic students during a clinical internship.

OBJECTIVE: The primary objective of this study was to describe the case mix experienced by chiropractic students during their clinical internship at the Canadian Memorial Chiropractic College. Secondary objectives were to characterize teaching clinic patient populations, assess the similarity to previously published data for practicing chiropractors, and describe the treatment plans being recommended by interns. METHODS: A prospective, observational study was conducted using a convenience sample of 24 chiropractic interns. Data were collected by interns using a standardized form that was completed for each new patient and each new complaint examined during the 1-year internship. Standardized forms included data regarding patient demographics, complaint characteristics, and treatment recommendations. RESULTS: Data were included for 23 of 24 participating interns, who described 828 patients and a total of 948 unique complaint presentations. Overall, 60% of patients were female, 86% were 18 to 64 years old, and 23% were naive to chiropractic care. Of all presenting complaints, 93% were pain-based, 67% were chronic, 65% included spinal complaints, and 7% presented with red flags; individual interns' experiences were variable and are described. On average, treatment recommendations called for 9.4 visits and often included multimodal treatment approaches, most commonly soft-tissue therapies (91%), home-based active care (84%), and spine manipulation (70%). CONCLUSIONS: The findings of this study suggest that patients presenting to CMCC teaching clinics are similar to those reported previously to attend private chiropractic clinics. While all participating interns encountered multiple complex clinical cases, very few had experience with pediatric populations. This study adds to the few that detail the characteristics of patients attending chiropractic teaching clinics; to our knowledge it is the first to describe average case loads of chiropractic interns.

The quality of placebos used in randomized, controlled trials of lumbar and pelvic joint thrust manipulation-a systematic review.

BACKGROUND CONTEXT: Spinal manipulative therapy (SMT) has been attributed with substantial non-specific effects. Accurate assessment of the non-specific effects of SMT relies on high-quality studies with low risk of bias that compare with appropriate placebos. PURPOSE: This review aims to characterize the types and qualities of placebo control procedures used in controlled trials of manually applied, lumbar and pelvic (LP)-SMT, and to evaluate the assessment of subject blinding and expectations. STUDY DESIGN: This is a systematic review of randomized, placebo-controlled trials. METHODS: We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Index to Chiropractic Literature, and relevant bibliographies. We included randomized, placebo or sham-controlled trials where the index treatment was manually applied LP-SMT. There were no restrictions on the type of condition being investigated. Two independent reviewers selected the studies, assessed study quality, and extracted the data. Relevant data were the type and quality of placebo control(s) used, the assessment of blinding and expectations, and the results of those assessments. RESULTS: Twenty-five randomized, placebo-controlled trials were included in this review. There were 18 trials that used a sham manual SMT procedure for their placebo control intervention; the most common approach was with an SMT setup but without the application of any thrust. One small pilot study used an unequivocally indistinguishable placebo, two trials used placebos that had been validated as inert a priori, and eight trials reported on the success of subject blinding. Risk of bias was high or unclear, for all included studies. CONCLUSIONS: Imperfect placebos are ubiquitous in clinical trials of LP-SMT, and few trials have assessed for successful subject blinding or balanced expectations of treatment success between active and control group subjects. There is thus a strong potential for unmasking of control subjects, unequal non-specific effects between active and control groups, and non-inert placebos in existing trials. Future trials should consider assessing the success of subject blinding and ensuring inertness of their placebo a priori, as a minimum standard for quality.

Diagnostic and treatment methods used by chiropractors: A random sample survey of Canada's English-speaking provinces.

OBJECTIVE: It is important to understand how chiropractors practice beyond their formal education. The objective of this analysis was to assess the diagnostic and treatment methods used by chiropractors in English-speaking Canadian provinces. METHODS: A questionnaire was created that examined practice patterns amongst chiropractors. This was sent by mail to 749 chiropractors, randomly selected and stratified proportionally across the nine English-speaking Canadian provinces. Participation was voluntary and anonymous. Data were entered into an Excel spreadsheet, and descriptive statistics were calculated. RESULTS: The response rate was 68.0%. Almost all (95.1%) of respondents reported performing differential diagnosis procedures with their new patients; most commonly orthopaedic testing, palpation, history taking, range of motion testing and neurological examination. Palpation and painful joint findings were the most commonly used methods to determine the appropriate joint to apply manipulation. The most common treatment methods were manual joint manipulation/mobilization, stretching and exercise, posture/ergonomic advice and soft-tissue therapies. CONCLUSIONS: Differential diagnosis is a standard part of the assessment of new chiropractic patients in English-speaking Canadian provinces and the most common methods used to determine the site to apply manipulation are consistent with current scientific literature. Patients are treated with a combination of manual and/or manipulative interventions directed towards the joints and/or soft-tissues, as well as exercise instruction and postural/ergonomic advice.

OBJECTIF: Il est important de comprendre la pratique des chiropraticiens qui dépasse le cadre de leur éducation formelle. L'objectif de cette analyse était d'évaluer les méthodes de diagnostic et de traitement utilisées par les chiropraticiens dans les provinces canadiennes anglophones. MÉTHODOLOGIE: Un questionnaire a été créé pour examiner les habitudes de pratique des chiropraticiens et a été envoyé par la poste à 749 d'entre eux, choisis au hasard et stratifiés proportionnellement entre les neuf provinces anglophones. La participation était volontaire et anonyme. Les données ont été saisies dans un tableur Excel, et les statistiques descriptives ont été calculées. RÉSULTATS: Le taux de participation a été de 68,0 %. Presque tous (95,1 %) les répondants ont déclaré effectuer des diagnostics différentiels de leurs nouveaux patients; plus couramment des tests orthopédiques, la palpation, l'anamnèse, des tests d'amplitude de mouvement et l'examen neurologique. La palpation et la détection d'articulations douloureuses étaient les méthodes les plus couramment utilisées pour déterminer l'articulation appropriée à manipuler. Les méthodes de traitement les plus fréquentes étaient la manipulation ou la mobilisation manuelle des articulations, les étirements et les exercices, les conseils posturaux ou ergonomiques et la thérapie des tissus mous. CONCLUSIONS: Le diagnostic différentiel fait partie de la norme d'évaluation de nouveaux patients chiropratiques dans les provinces anglophones canadiennes, et les méthodes les plus couramment utilisées pour déterminer les points à manipuler concordent avec les publications scientifiques actuelles. Les patients sont traités par une combinaison d'interventions manuelles ou de manipulation axées sur les articulations ou tissus mous, ainsi que par des instructions d'exercice et des conseils posturaux et ergonomiques.

Relationship between chiropractic teaching institutions and practice characteristics among Canadian doctors of chiropractic: a random sample survey.

OBJECTIVE: The objectives of this study were to determine if faction membership among Canadian doctors of chiropractic (DCs) is associated with differences in educational program characteristics among English-speaking Canadian and United States chiropractic colleges and to determine if those differences are expressed in terms of surveyed attitudes and behaviors regarding treatment efficacy, radiographic imaging, vaccinations, and interprofessional referrals. This study also aims to identify if educational programs may be a potential source of multiple professional identities. METHODS: A randomly selected sample of Canadian DCs, stratified across the English-speaking provinces, was surveyed by mail. Survey items included school of graduation, self-categorization by chiropractic subgroup, perceptions of condition-specific treatment efficacy, use of plain film radiographic imaging, vaccination attitudes/behaviors, and patient referral patterns. Self-categorization by chiropractic subgroup included: the unorthodox faction (associates the chiropractic subluxation as an encumbrance to the expression of health) and the orthodox perspective (associates with musculoskeletal joint dysfunction, public health, and lifestyle concerns). For data analysis, chiropractic schools were divided into 2 groups according to location: English-speaking Canada and the US. The US was further clustered into liberal ("interested in mixing elements of modern and alternative therapies into the practice of chiropractic") and conservative categories ("chiropractors who believe in continuing the traditions of chiropractic"). RESULTS: Of 740 deliverable questionnaires, 503 were returned for a response rate of 68%. χ(2) Testing revealed significant differences in self-categorized faction membership associated with the clustering of colleges based on ideological viewpoints (χ(2) = 27.06; P = .000). Descriptive results revealed a relationship between school of origin and perceived treatment efficacy, use of radiographic imaging, and vaccination attitudes. No significant differences were found relative to interprofessional referral patterns. CONCLUSION: Chiropractic program attended is a significant predictor of orthodox vs unorthodox faction membership and professional practice characteristics for Canadian DCs. This suggests that the current chiropractic education system may contribute to multiple professional identities.

Differentiating intraprofessional attitudes toward paradigms in health care delivery among chiropractic factions: results from a randomly sampled survey.

BACKGROUND: As health care has increased in complexity and health care teams have been offered as a solution, so too is there an increased need for stronger interprofessional collaboration. However the intraprofessional factions that exist within every profession challenge interprofessional communication through contrary paradigms. As a contender in the conservative spinal health care market, factions within chiropractic that result in unorthodox practice behaviours may compromise interprofessional relations and that profession's progress toward institutionalization. The purpose of this investigation was to quantify the professional stratification among Canadian chiropractic practitioners and evaluate the practice perceptions of those factions. METHODS: A stratified random sample of 740 Canadian chiropractors was surveyed to determine faction membership and how professional stratification could be related to views that could be considered unorthodox to current evidence-based care and guidelines. Stratification in practice behaviours is a stated concern of mainstream medicine when considering interprofessional referrals. RESULTS: Of 740 deliverable questionnaires, 503 were returned for a response rate of 68%. Less than 20% of chiropractors (18.8%) were aligned with a predefined unorthodox perspective of the conditions they treat. Prediction models suggest that unorthodox perceptions of health practice related to treatment choices, x-ray use and vaccinations were strongly associated with unorthodox group membership (X(2) =13.4, p = 0.0002). CONCLUSION: Chiropractors holding unorthodox views may be identified based on response to specific beliefs that appear to align with unorthodox health practices. Despite continued concerns by mainstream medicine, only a minority of the profession has retained a perspective in contrast to current scientific paradigms. Understanding the profession's factions is important to the anticipation of care delivery when considering interprofessional referral.

Short-term effects of manipulation to the upper thoracic spine of asymptomatic subjects on plasma concentrations of epinephrine and norepinephrine-a randomized and controlled observational study.

OBJECTIVE: The purpose of this study was to investigate the short-term effects of spinal manipulation applied to a hypomobile segment of the upper thoracic spine (T1-T6), on plasma concentrations of norepinephrine (NE) and epinephrine (E) in asymptomatic subjects, under strictly controlled conditions. METHODS: Fifty-six asymptomatic subjects were randomly assigned to receive either a chiropractic manipulative intervention or a sham intervention in the upper thoracic spine. A 20-gauge catheter fitted with a saline lock was used to sample blood before, immediately after, and 15 minutes after intervention. Plasma NE and E concentrations were determined using an enzyme-linked immunosorbent assay. Changes in plasma catecholamine concentrations were analyzed within and between groups using 1- and 2-sample t tests, respectively. RESULTS: The plasma samples of 36 subjects (18 treatment, 18 control) were used in the analysis. Mean plasma concentrations of NE and E did not significantly differ between the 2 groups at any time point and did not change significantly after either the manipulative or sham intervention. CONCLUSIONS: The results of this study indicate that a manipulative thrust directed to a hypomobile segment in the upper thoracic spine of asymptomatic subjects does not have a measurable effect on the plasma concentrations of NE or E. These results provide a baseline measure of the sympathetic response to spinal manipulation.

Cross-frictional therapy and stretching for the treatment of palmar adhesions due to Dupuytren's contracture: a prospective case study.

OBJECTIVE: To examine the potential for treatment of palmar adhesions associated with Dupuytren's contracture using instrument-assisted cross-frictional massage (CFM) and stretching. METHODS: This was a prospective case study. The primary intervention consisted of a 2-min multi-planar CFM over the affected area of the palm, followed by a 2-min maximal finger-extension stretch. RESULTS: Following eight weeks of treatment there were increases in both passive and active extension range of motion of the digits, reduction in the visibility of palmar adhesions, and subjective improvements in hand function. CONCLUSIONS: This treatment protocol may offer a substitute for the current invasive surgical and injection procedures that are available.

An examination of the observed placebo effect associated with the treatment of low back pain - a systematic review.

OBJECTIVE: To determine whether the nonspecific effects that occur following the use of sham interventions to treat nonspecific low back pain (LBP) are large enough to be considered clinically meaningful. DESIGN: Electronic databases were searched systematically for randomized placebo-controlled trials of interventions for LBP that used sham ultrasound, sham laser or sham drug therapy as the placebo control. Study selection was accomplished via independent evaluation of scientific admissibility by three reviewers and final decisions of inclusion were based on consensus. RESULTS: None of the studies using sham ultrasound as the placebo control in the treatment of LBP were acceptable for inclusion. Twelve studies were included in the present evaluation of the placebo effect - eight trials that met the strict inclusion criteria for best evidence (three using sham laser placebo and five using sham medication placebo) and four sham medication studies that 'just missed' the inclusion criteria for best evidence. Although the evidence from studies using sham laser was inconclusive, the present review did find a clinically meaningful change in LBP scores following the use of sham oral medications. CONCLUSIONS: The present best-evidence review found a clinically meaningful change in pain scores following the use of sham oral medications for the treatment of nonspecific LBP. This finding suggests that further clinical research is warranted to identify which patient subgroups could benefit most from such treatment and to distinguish the true contribution of the placebo effect from other nonspecific effects.

An investigation of bacterial contamination on treatment table surfaces of chiropractors in private practice and attitudes and practices concerning table disinfection.

BACKGROUND: The attitudes and behaviors of chiropractors regarding table disinfection have not yet been investigated. The purpose of this study was to evaluate (1) the bacterial contaminants present on treatment tables in private chiropractic clinics, (2) the effectiveness of the paper barrier in preventing bacterial deposition, and (3) chiropractors' attitudes and practices regarding table disinfection. METHODS: Defined portions of treatment tables from 14 private clinics in Alberta, Canada were sampled for the presence of bacteria. Growth characteristics and 16S rRNA gene sequencing were used for bacterial identification. In addition, a 12-item survey was administered to southern Alberta chiropractors (n = 79; 81% response rate) inquiring about their attitudes and behaviors regarding table disinfection. RESULTS: Respondents favored the idea of table disinfection (84%), but only 62% had a routine disinfection protocol. Table sampling revealed the presence of a number of bacteria, including methicillin-resistant Staphylococcus aureus, which were recovered from 3 separate clinics. The paper covering on table headpieces was an effective barrier to bacteria. CONCLUSION: Chiropractors have a positive attitude regarding disinfection; however, the risk of infection from treatment tables remains. Modification of the positioning of facial piece paper may be indicated, along with increased emphasis on disinfection.

Actinomadura keratinilytica sp. nov., a keratin-degrading actinobacterium isolated from bovine manure compost.

A novel keratinolytic actinobacterium, strain WCC-2265(T), was isolated from bovine hoof keratin 'baited' into composting bovine manure from southern Alberta, Canada, and subjected to phenotypic and genotypic characterization. Strain WCC-2265(T) produced well-developed, non-fragmenting and extensively branched hyphae within substrates and aerial hyphae, from which spherical spores possessing spiny cell sheaths were produced in primarily flexuous or straight chains. The cell wall contained meso-diaminopimelic acid, whole-cell sugars were galactose, glucose, madurose and ribose, and the major menaquinones were MK-9(H(6)), MK-9(H(8)), MK-9(H(4)) and MK-9(H(2)). These characteristics suggested that the organism belonged to the genus Actinomadura and a comparative analysis of 16S rRNA gene sequences indicated that it formed a distinct clade within the genus. Strain WCC-2265(T) could be differentiated from other species of the genus Actinomadura by DNA-DNA hybridization, morphological and physiological characteristics and the predominance of iso-C(16 : 0), iso-C(17 : 0) and 10-methyl C(17 : 0) fatty acids. The broad range of phenotypic and genetic characters supported the suggestion that this organism represents a novel species of the genus Actinomadura, for which the name Actinomadura keratinilytica sp. nov. is proposed; the type strain is strain WCC-2265(T) (=DSM 45195(T)=CCUG 56181(T)).

Stereospecificity of myo-inositol hexakisphosphate hydrolysis by a protein tyrosine phosphatase-like inositol polyphosphatase from Megasphaera elsdenii.

Inositol polyphosphatases (IPPases), particularly those that can hydrolyze myo-inositol hexakisphosphate (Ins P(6)), are of biotechnological interest for their ability to reduce the metabolically unavailable organic phosphate content of feedstuffs and to produce lower inositol polyphosphates (IPPs) for research and pharmaceutical applications. Here, the gene coding for a new protein tyrosine phosphatase (PTP)-like IPPase was cloned from Megasphaera elsdenii (phyAme), and the biochemical properties of the recombinant protein were determined. The deduced amino acid sequence of PhyAme is similar to known PTP-like IPPases (29-44% identity), and the recombinant enzyme displayed strict specificity for IPP substrates. Optimal IPPase activity was displayed at an ionic strength of 250 mM, a pH of 5.0, and a temperature of 60 degrees C. In order to elucidate its stereospecificity of Ins P(6) dephosphorylation, a combination of high-performance ion-pair chromatography and kinetic studies was conducted. PhyAme displayed a stereospecificity that is unique among enzymes belonging to this class in that it preferentially cleaved Ins P(6) at one of two phosphate positions, 1D-3 or 1D-4. PhyAme followed two distinct and specific routes of hydrolysis, predominantly degrading Ins P(6) to Ins(2)P via: (a) 1D-Ins(1,2,4,5,6)P(5), 1D-Ins(1,2,5,6)P(4), 1D-Ins(1,2,6)P(3), and 1D-Ins(1,2)P(2) (60%) and (b) 1D-Ins(1,2,3,5,6)P(5), 1D-Ins(1,2,3,6)P(4), Ins(1,2,3)P(3), and D/L-Ins(1,2)P(2)(35%).

Kinetics, substrate specificity, and stereospecificity of two new protein tyrosine phosphatase-like inositol polyphosphatases from Selenomonas lacticifex.

Inositol polyphosphatases (IPPases) play an important role in the metabolism of inositol polyphosphates, a class of molecules involved in signal transduction. Here we characterize 2 new protein tyrosine phosphatase-like IPPases (PhyAsl and PhyBsl) cloned from Selenomonas lacticifex that can hydrolyze myo-inositol hexakisphosphate (InsP6) in vitro. To determine their preferred substrates and stereospecificity of InsP6 dephosphorylation, a combination of kinetic and high-performance ion pair chromatography studies were conducted. Despite only 33% amino acid sequence identity between them, both enzymes display strict specificity for IPP substrates and cleave InsP6 primarily at the D-3-phosphate position (>90%). Furthermore, both enzymes predominantly degrade InsP6 to Ins(2)P via identical and very specific routes of dephosphorylation (3,4,5,6,1). Despite these similarities, PhylAsl is shown to have a slight kinetic preference for the major inositol pentakisphosphate intermediate in its InsP6 hydrolysis pathway, whereas PhyBsl displays a unique and substantial preference for an inositol tetrakisphosphate intermediate.

A protein tyrosine phosphatase-like inositol polyphosphatase from Selenomonas ruminantium subsp. lactilytica has specificity for the 5-phosphate of myo-inositol hexakisphosphate.

Although it is becoming well known that myo-inositol polyphosphates and the enzymes involved in their metabolism play a critical role in eukaryotic systems, little is understood of their significance in prokaryotic systems. A novel protein tyrosine phosphatase (PTP)-like inositol polyphosphatase (IPPase) gene has been cloned from Selenomonas ruminantium subsp. lactilytica (phyAsrl). The deduced amino acid sequence of PhyAsrl is most similar to a PTP-like IPPase from the anaerobic bacterium S. ruminantium (35% identity), but also shows similarity (19-30% identity) to various other putative prokaryotic PTPs. Recombinant PhyAsrl could dephosphorylate myo-inositol hexakisphosphate (Ins P(6)) in vitro, and maximal activity was displayed at an ionic strength of 200 mM, a pH of 4.5, and a temperature of 55 degrees C. In order to elucidate its substrate specificity and pathway of Ins P(6) dephosphorylation, a combination of kinetic and high-performance ion-pair chromatography studies were conducted. The data indicated that PhyAsrl has a general specificity for polyphosphorylated myo-inositol substrates, but can also dephosphorylate molecules containing high energy pyrophosphate bonds in vitro. PhyAsrl is unique from other microbial IPPases in that it preferentially cleaves the 5-phosphate position of Ins P(6). Furthermore, it can produce Ins(2)P via a highly unique and ordered pathway of sequential dephosphorylation: Ins P(6), Ins(1,2,3,4,6)P(5), D-Ins(1,2,3,6)P(4), Ins(1,2,3)P(3), and D/L-Ins(1,2)P(2). Finally, reverse transcription PCR was used to determine that phyAsrl is constitutively expressed, and together with bioinformatic analysis, was used to gain an understanding of its physiological significance.

Kinetic and structural analysis of a bacterial protein tyrosine phosphatase-like myo-inositol polyphosphatase.

PhyA from Selenomonas ruminantium (PhyAsr), is a bacterial protein tyrosine phosphatase (PTP)-like inositol polyphosphate phosphatase (IPPase) that is distantly related to known PTPs. PhyAsr has a second substrate binding site referred to as a standby site and the P-loop (HCX5R) has been observed in both open (inactive) and closed (active) conformations. Site-directed mutagenesis and kinetic and structural studies indicate PhyAsr follows a classical PTP mechanism of hydrolysis and has a broad specificity toward polyphosphorylated myo-inositol substrates, including phosphoinositides. Kinetic and molecular docking experiments demonstrate PhyAsr preferentially cleaves the 3-phosphate position of Ins P6 and will produce Ins(2)P via a highly ordered series of sequential dephosphorylations: D-Ins(1,2,4,5,6)P5, Ins(2,4,5,6)P4, D-Ins(2,4,5)P3, and D-Ins(2,4)P2. The data support a distributive enzyme mechanism and suggest the PhyAsr standby site is involved in the recruitment of substrate. Structural studies at physiological pH and high salt concentrations demonstrate the "closed" or active P-loop conformation can be induced in the absence of substrate. These results suggest PhyAsr should be reclassified as a D-3 myo-inositol hexakisphosphate phosphohydrolase and suggest the PhyAsr reaction mechanism is more similar to that of PTPs than previously suspected.