The short golf backswing: Effects on performance and spinal health implications

BACKGROUND: Full recoil golf swings have been implicated in back pain and injury in golfers. Evidence suggests that a restricted backswing may reduce the potential for injury without compromising performance. OBJECTIVE: To examine both golf swing performance and selected muscular actions of the trunk and shoulder during a full recoil swing as compared with a modified short backswing. METHODS: Electromyographic (EMG) recordings were taken bilaterally from the lumbar, external oblique, latissimus dorsi, and right pectoral muscles in 7 golfers during a full recoil swing and a modified short backswing. High-speed videotape was used to measure back swing angle reduction. Clubhead velocity (CHV) and ball-contact accuracy were quantified by using a swing speed indicator and clubface contact tape, respectively. RESULTS: Shortening of the backswing by 46.5 degrees +/- 24.7 degrees had no effect on stroke accuracy as measured by mean deviation from the target spot on the club (19.0 +/- 7.8 mm vs 19.3 +/- 9.2 mm). CHV was not significantly reduced (33.9 +/- 2.5 m/s vs 31.2 +/- 2.2 m/s). However, EMG root-mean-square was decreased 19% in the right oblique muscle from 750 to 250 ms before impact (P < .05). During the acceleration phase, activation of left lumbar muscle decreased by 12%, whereas activation of right latissimus muscle increased by 21%. Although left lumbar muscle activity during the follow-through increased 14%, there was a substantial (17%) but nonsignificant decrease of activation of trunk muscles (P = .11). There was a general trend toward an increased activation of the shoulder musculature from 250 ms before impact to 500 ms after impact. CONCLUSION: These data support the idea that short backswings in golf may reduce trunk muscle activation and possibly reduce back injury and pain without negatively impacting swing accuracy or CHV. However, the short swing increases shoulder muscle activation and may, in turn, promote risk for shoulder injury.     

Clinicopathologic Conference

Hiatal hernia, a great mimic of other lesions, is one of the most common causes of substernal and upper abdominal complaints in middle-aged and older persons, and frequently is associated with angina pectoris, degenerative cardiovascular disease, gallbladder disease or peptic ulcer. Concomitant hiatal hernia and peptic ulcer can result in complications such as reflux esophagitis, esophageal ulcer and stenosis; hiatal hernia associated with coronary artery disease can precipitate angina.     

Body composition in paraplegic male athletes

The body composition and anthropometric characteristics of male paraplegic athletes (PARA, N = 22) were contrasted to an able-bodied ectomorphic (N = 22) and mesomorphic (N = 31) comparison group of moderately and highly trained male subjects. The validity of 12 body composition [density (Db)] prediction equations reported in the literature, 4 generalized, were determined (tested) on this special group of athletes (PARA). On the whole, the prediction equations over-predicted Db in PARA by 0.0039 to 0.0166 g X cm-3 (under-predicted relative fat by 1.8 to 7.4%). Five diameter, 11 circumference, and 7 skinfold measures were used in a SAS-STEPWISE multiple regression procedure with hydrostatically determined Db to develop several suitable Db prediction equations for the paraplegic athlete. Diameters were poor predictors (r = 0.60, SEE = 0.0164), while skinfolds, circumferences, or a combination of measures were acceptable, with the combined equation being best (r = 0.95, SEE = 0.0064). The findings of this study suggest that even generalized equations do not adequately predict Db in PARA and that paraplegic specific equations are presently best suited for predicting Db in paraplegic athletes. The results further indicate that although these equations meet many of the criteria of Lohman, the SEE and total error values are unusually high and make prediction of body composition using anthropometry in a heterogeneous group of PARA athletes slightly unreliable.     

60Co aqueous speciation and pH effect on the adsorption behavior on inorganic materials.

The adsorption of radioactive cobalt from aqueous solution on MgO, MnO(2), TiO(2), SnO, activated carbon and calcined hydrotalcite was studied under static conditions as a function of pH (1, 3, 5, 7, and 10) of the (60)Co solution. It was found that under the experimental conditions, (60)Co was significantly adsorbed on MnO(2), TiO(2) and activated carbon and in smaller quantities on MgO, SnO and calcined hydrotalcite. The adsorption of (60)Co species on MgO, MnO(2), TiO(2) and SnO can be attributed to the direct exchange of ions with a specific group on the adsorbing surface, in accordance with the concept of zero point charge (zpc). The radionuclide content was determined by gamma-spectrometry. The (60)Co chemical species present in aqueous solutions with different pH values were surveyed by using high-voltage electrophoresis. It was also found that (60)Co was present only as a cationic species at pH 1, 3, 5 and 7 and a neutral species at alkaline pH.     

Spinal reflex attenuation associated with spinal manipulation

STUDY DESIGN: This study evaluated the effect of lumbosacral spinal manipulation with thrust and spinal mobilization without thrust on the excitability of the alpha motoneuronal pool in human subjects without low back pain. OBJECTIVES: To investigate the effect of high velocity, low amplitude thrust, or mobilization without thrust on the excitability of the alpha motoneuron pool, and to elucidate potential mechanisms in which manual procedures may affect back muscle activity. SUMMARY OF BACKGROUND DATA: The physiologic mechanisms of spinal manipulation are largely unknown. It has been proposed that spinal manipulation may reduce back muscle electromyographic activity in patients with low back pain. Although positive outcomes of spinal manipulation intervention for low back pain have been reported in clinical trials, the mechanisms involved in the amelioration of symptoms are unknown. METHODS: In this study, 17 nonpatient human subjects were used to investigate the effect of spinal manipulation and mobilization on the amplitude of the tibial nerve Hoffmann reflex recorded from the gastrocnemius muscle. Reflexes were recorded before and after manual spinal procedures. RESULTS: Both spinal manipulation with thrust and mobilization without thrust significantly attenuated alpha motoneuronal activity, as measured by the amplitude of the gastrocnemius Hoffmann reflex. This suppression of motoneuronal activity was significant (P < 0.05) but transient, with a return to baseline values exhibited 30 seconds after intervention. CONCLUSIONS: Both spinal manipulation with thrust and mobilization without thrust procedures produce a profound but transient attenuation of alpha motoneuronal excitability. These findings substantiate the theory that manual spinal therapy procedures may lead to short-term inhibitory effects on the human motor system.     

Responsiveness of the Bournemouth and Oswestry questionnaires: a prospective pilot study

BACKGROUND: The assessment of health-related quality-of-life outcome information has become an essential feature in the delivery of quality health care. Outcome assessment and increased clinical research capacity have been identified as recommended areas of priority for chiropractic research, chiropractic colleges, and the profession. OBJECTIVE: This article reports the results of a multisite pilot project utilizing New York Chiropractic College's 3 off-campus health centers. In the project, we sought to examine generic issues related to research infrastructure and feasibility, perform pilot testing of the responsiveness of the revised Oswestry Disability Index (ODI) and the Bournemouth Questionnaire (BQ), and develop estimates of change and population size for the possible future projects. METHODS: We describe the infrastructure created to conduct the project, including an on-site clinician research manager; on-site student research assistants; identification, recruitment, and patient flow; demographic and clinical characteristics; and abstraction instruments. Responsiveness study subjects completed 3 health-related quality-of-life assessments at baseline, 15 days, and 30 days. At 45 days, or at discharge, subjects completed the same questionnaires and a global rating of change. Responsiveness is reported by analysis of standardized estimates of change, relative efficiency, and receiver operator characteristic (ROC) curve plots. RESULTS: We successfully identified 82% of possible study patients; the real eligibility rate in our population was 30%. In 4 months, 70 patients were accrued, and 26 patients followed through to provide global ratings of change scores. Responsiveness by standardized change scores was numerical rating scale (NRS) = 1.19, ODI = 0.91, BQ = 0.78; by relative efficiency it was BQ/ODI = 0.86, ODI/NRS = 0.76, BQ/NRS = 0.66. Area under the curves ranged from 0.69 for the BQ to 0.86 for the NRS. CONCLUSIONS: Recommendations for modification and use of the infrastructure, research capacity, and future outcome and appropriateness assessment projects are offered.     

Endogenous opioid effects on motoneuron pool excitability: potential analgesic effect of acute exercise

BACKGROUND: Metabolic and thermal stresses of exercise mediate the release of endogenous opioids depressing motoneuron activation (MNA). Although exercise is routinely presented as a coequal treatment for management of acute and chronic low back pain (LBP), it is not clear that exercise-induced endogenous opioid release can play a role in the analgesic and treatment outcomes for patients with LBP. Furthermore, if opioid involvement is present, it is not clear what level of exercise might be beneficial in the suppression of MNA and possibly LBP. OBJECTIVE: To determine whether exercise-induced endogenous opioid release can play a role in the analgesic and treatment outcomes for patients with LBP and to determine what level of exercise might be beneficial in the suppression of MNA and possibly LBP. METHODS: To test this hypothesis, male (n = 3) and female (n = 3) healthy volunteers were tested 6 times over a 4-week period. The 6 trials included high-intensity treadmill exercise at 75% O(2max) with placebo or naloxone, low-intensity exercise at 40% O(2max) (placebo or naloxone) and no exercise control (placebo or naloxone). The evoked spinal Hoffmann H-reflex (soleus muscle) was measured as the criterion for MNA before and after exercise and expressed with the maximal M-wave as the maximal H(max)/M(max) percent ratio. Naloxone (10 mg) or isovolumic saline solution was administered double-blind (1 mL bolus) after recovery from exercise and before H-reflex measurement. RESULTS: The results show a significant reduction in the H(max)/M(max) percent ratio for both exercise conditions (40.0 +/- 7.1 to 33.9 +/- 9.1% for 75% O(2max) and 37.4 +/- 4.8 to 33.0 +/- 5.3% for 40% O(2max); P <.01). Naloxone treatment did not attenuate the exercise-induced H(max)/M(max) percent ratio suppression. CONCLUSION: Endogenous opioids do not appear to modulate motoneuron responses to exercise under these experimental conditions.     

Congenital Anomalies of the Heart and Great Vessels

For general practitioners, in whose practice is included a major proportion of the medical management of infants and children, and for the specializing pediatrician as well, Postgraduate Medicine presents this special regular department devoted to brief discussions by recognized authorities on their preferred methods of the treatment and management of diseases and problems of infancy and childhood.