Physical performance in persons with spinal cord injuries after discharge from rehabilitation.

PURPOSE: The purpose of this study was to investigate changes in physical capacity and performance of activities of daily living (ADL) during the postrehabilitation period of persons with spinal cord injuries and to determine the factors explaining the changes in physical capacity. METHODS: Nine subjects with tetraplegia and 11 subjects with paraplegia were measured at time of discharge from rehabilitation (t1) and on average 1.2 yr later (t2). Physical capacity was measured as maximal isometric strength (F(iso)), sprint power output (P30), maximal power output (POmax), and peak oxygen uptake (VO2peak). Physical strain and performance time were measured during standardized ADL (ascending ramp, passing door, making transfer, washing hands). RESULTS: P30 and POmax showed a significant increase at t2, whereas F(iso) and VO2peak remained unchanged. Sport activity was the most important independent variable explaining relative changes in P30 and POmax, showing on average larger values in active subjects. Other independent variables that were significantly related to changes in physical capacity were the occurrence of illness and having a tetraplegia (negatively associated with changes in P30 and VO2peak), and incompleteness of the lesion and an increased body mass (positively associated with changes in F(iso)). Increase in physical capacity was found to coincide with decrease of the physical strain and performance time of ADL, reflected in significant negative correlation coefficients for some tasks. CONCLUSIONS: It is concluded that physical capacity and performance of ADL improved or remained constant during the first year after rehabilitation and that sport participation is associated with improvements in physical capacity. Results of this study underline the importance of being physically active during the period after rehabilitation of persons with spinal cord injuries.     

A hypothesis: radiation carcinogenesis may result from tissue injuries and subsequent recovery processes which can act as tumor promoters and lead to an earlier onset of cancer

Cancer risks from radiation can be observed as an increase in mortality when compared to a control group. However, it is unknown if this increased risk results from the induction of cancer or from an earlier onset of cancer. In mouse studies, it has been repeatedly shown that after an irradiation, the survival curve is shifted toward lower ages, but remains parallel to the control curve, and the extent of the shift in time to lower ages is dose-dependent. This shift is not satisfactorily explained by the induction model which assumes that cancers in the exposed group consist of spontaneous and induced events. Consequently, it seems that this shift could be interpreted to mean that all animals in the exposed group had suffered from life shortening. Under this scenario, however, it turns out that the radiation effects can no longer be interpreted as the result of oncogenic mutations, because these effects would have to involve all tumors, and the effectiveness of radiation changes with the dose. This leads to the speculation that radiation exposures induce a broad range of tissue injuries, and that these injuries are subsequently subjected to longlasting systemic recovery processes which act as promoters for tumor cells. In other words, potential cancer stem cells which were located in the irradiated field can escape oncogenic damage but undergo stimulation later in life toward the development of malignancy from radiation-induced activated microenvironment. This is an unusual form of the non-targeted or bystander effects of radiation. It is worth noting that this model suggests that there could be a path or paths which could be used to intervene in the process of post-exposure carcinogenesis, and that cancer risks at low doses could be described as days or weeks of life lost.     

Selection and classification of high school volleyball players from performance tests.

The purpose of this study were to determine the accuracy of general and specific tests for identifying the players on freshmen (FR), junior varsity (JV), and varsity (VR) teams and the precision of tests to differentiate between starters and nonstarters at each level of play. Fifty high school volleyball players were tested during the first week of practice for six general and four specific motor performance tests. The specific tests included the overhead volley, forearm pass, wall spike, and self bump/set test. The general tests included height, weight, percent body fat, agility run, vertical jump, and two flexibility maneuvers. VR players were significantly better in vertical jump, agility, and all specific ball-handling tests than FR and VJ players. The combination of forearm pass, overhead volley, vertical jump, and weight correctly classified 68% of the players to their team level. The combination of bump-set, height, weight, and shoulder flexibility allowed correct classification of 78% of the starters and nonstarters. General and specific tests can successfully select and classify high school volleyball players.     

Left ventricular perfusion and performance from a single radiopharmaceutical and one camera.

To test the hypothesis that a small field of view portable multicrystal scintillation camera can perform stress/rest combined LV function by first-pass and perfusion studies using 99mTc-teboroxime, 26 patients with positive stress thallium studies within 2 wk and 8 healthy volunteers were studied. A 241Am point source marker over the sternum was used for motion correction. Dynamic dual-isotope (99mTc/241Am) acquisition was performed following injection of 15.6 +/- 2.3 mCi of 99mTc-teboroxime at peak treadmill exercise. Two minutes later (blood-pool clearance), while still standing on the flat treadmill, 3-4 40-sec planar images were acquired. One hour later patients were reinjected with 22.7 +/- 3.4 mCi of 99mTc-teboroxime while standing in front of the camera and the same dynamic/static acquisition protocol repeated. The planar images were interpolated from a 20 x 20 matrix to a 160 x 160 matrix, a sharpening filter and an interpolative background subtraction algorithm applied. The scans were divided into segments, each scored as normal, reversible and fixed. The agreement with thallium imaging for identifying an abnormal scan was 24/26 (92%) and for identifying abnormal vascular territories was 43/52, (83%). Fourteen patients had exercise LVEF less than 50% and all had either prior myocardial infarction, myocardial infarction plus ischemia or LAD ischemia. Diagnostic planar perfusion images and exercise LVEF can be acquired in less than 4 min using 99mTc-teboroxime and a portable multicrystal scintillation camera.     

'Lessons learnt from America'--Reflections from a fellowship examining the prevention, recognition and treatment of operational stress injuries in U.S. Army serving personnel

These are my personal views and reflections from a hugely rewarding experience. They are not opinions or recommendations of the MOD or any other institution I am associated with. I realise that there may be various logistical reasons why my recommendations cannot be carried out; however I do hope that some will be able to be put into place. If nothing else I gained a massive amount from my travelling fellowship and it has already had a positive impact on my own clinical work. I hope to continue to pass on what I have learnt from the fellowship for many years to come. A special thank you goes to the Winston Churchill Memorial Trust for providing me with this fantastic opportunity and everyone who helped me before and during my visit.     

Physical fitness and performance. Cardiorespiratory fitness in girls-change from middle to high school

PURPOSE: To determine how factors are related to change in cardiorespiratory fitness (CRF) across time in middle school girls followed through high school. METHODS: Adolescent girls (N = 274, 59% African American, baseline age = 13.6 +/- 0.6 yr) performed a submaximal fitness test (PWC170) in 8th, 9th, and 12th grades. Height, weight, sports participation, and physical activity were also measured. Moderate-to-vigorous physical activity (MVPA) and vigorous physical activity (VPA) were determined by the number of blocks reported on the 3-Day Physical Activity Recall (3DPAR). Individual differences and developmental change in CRF were assessed simultaneously by calculating individual growth curves for each participant, using growth curve modeling. RESULTS: Both weight-relative and absolute CRF increased from 8th to 9th grade and decreased from 9th to 12th grade. On average, girls lost 0.16 kg.m.min.kg.yr in weight-relative PWC170 scores (P < 0.01) and gained 10.3 kg.m.min.yr in absolute PWC170 scores. Girls reporting two or more blocks of MVPA or one or more blocks of VPA at baseline showed an average increase in PWC170 scores of 0.40-0.52 kg.m.min.kg.yr (weight relative) and 22-28 kg.m.min.yr (absolute) in CRF. In weight-relative models, girls with higher BMI showed lower CRF (approximately 0.37 g.m.min.kg.yr), but this was not shown in absolute models. In absolute models, white girls (approximately 40 kg.m.min.yr) and sport participants (approximately 28 kg.m.min.yr) showed an increase in CRF over time. CONCLUSION: Although there were fluctuations in PWC170 scores across time, average scores decreased during 4 yr. Physical activity was related to change in CRF over time; BMI, race, and sport participation were also important factors related to change over time in CRF (depending on expression of CRF-weight-relative vs absolute). Subsequent research should focus on explaining the complex longitudinal interactions between CRF, physical activity, race, BMI, and sports participation.     

Height, weight, and BMI predict intra-articular injuries observed during ACL reconstruction: evaluation of 456 cases from a prospective ACL database.

OBJECTIVE: To identify demographic and anthropometric risk factors for intra-articular (IA) injuries observed during ACL reconstruction. We hypothesize that significant associations exist among height, weight, and body mass index (BMI) with IA injuries when ACL tear occurs. DESIGN: This observational study of a prospective multi-investigator ACL database used logistic and Poisson regression analysis to assess independent predictors of IA injuries. SETTING: Vanderbilt Sports Medicine and affiliated tertiary care center. PATIENTS: Patients undergoing unilateral ACL reconstruction without prior injury to either knee were identified from a detailed prospective ACL reconstruction database. Four hundred fifty-six patients met inclusion/exclusion criteria. INTERVENTIONS: Per inclusion criteria, all patients underwent unilateral ACL reconstruction after assessment of injury profile. MAIN OUTCOME MEASUREMENTS: The ACL database was initiated in 1990 to identify demographic, anthropometric, and mechanistic variables associated with intra-articular injury. RESULTS: Height best predicted tibial and patellar damage. BMI better predicted medial femoral condyle lesions, whereas weight better predicted lateral and patellofemoral injury. BMI and weight equally predicted injury to menisci and medial tibial plateau. Through different outcomes, age (odd ratio [OR], 1.49; 95% CI, 1.02-2.16), height (OR, 2.66; 95% CI, 1.52-4.65), weight (OR, 1.02; 95% CI, 1.01-1.04), and BMI (OR, 1.24; 95% CI, 1.004-1.53) were all significant predictors of intra-articular injury. CONCLUSIONS: This is the first report using multivariable analysis of age, height, weight, and BMI to evaluate associations with IA injuries after ACL rupture observed during ACL reconstruction. We hypothesize that athletes possibly could reduce risk of certain IA pathologies with maintenance of lower body weight and BMI and thus potentially improve long-term functional outcomes after ACL reconstruction.     

Transitioning from daytime to nighttime operations in military training has a temporary negative impact on dynamic balance and jump performance in U.S. Army Rangers

ObjectivesExplore the impact transitioning from daytime to nighttime operations has on performance in U.S. Army Rangers.MethodsFifty-four male Rangers (age 26.1 ± 4.0 years) completed the Y-Balance Test (YBT), a vertical jump assessment, and a grip strength test at three time points. Baseline testing occurred while the Rangers were on daytime operations; post-test occurred after the first night into the nighttime operation training (after full night of sleep loss), and follow-up testing occurred six days later (end of nighttime training).ResultsOn the YBT, performance was significantly worse at post-test compared to baseline during right posteromedial reach (104.1 ± 7.2 cm vs 106.5 ± 6.7 cm, p = .014), left posteromedial reach (105.4 ± 7.5 cm vs 108.5 ± 6.6 cm, p = .003), right composite score (274.8 ± 19.3 cm vs 279.7 ± 18.1 cm, p = .043), left composite score (277.9 ± 18.1 cm vs 283.3 ± 16.7 cm, p = .016), and leg asymmetry was significantly worse in the posterolateral direction (4.8 ± 4.0 cm vs 3.7 ± 3.1 cm, p = .030) and the anterior direction (5.0 ± 4.0 cm vs 3.6 ± 2.6 cm, p = .040). The average vertical jump height was significantly lower at post-test compared to baseline (20.6 ± 3.4 in vs 21.8 ± 3.0 in, p = .004). Baseline performance on YBT and vertical jump did not differ from follow-up.ConclusionsArmy Rangers experienced an immediate, but temporary, drop in dynamic balance and vertical jump performance when transitioning from daytime to nighttime operations. When feasible, Rangers should consider adjusting their sleep cycles prior to anticipating nighttime operations in order to maintain their performance levels. Investigating strategies that may limit impairments during this transition is warranted.