The effects of rehabilitation on the muscles of the trunk following prolonged bed rest.

Microgravity and inactivity due to prolonged bed rest have been shown to result in atrophy of spinal extensor muscles such as the multifidus, and either no atrophy or hypertrophy of flexor muscles such as the abdominal group and psoas muscle. These effects are long-lasting after bed rest and the potential effects of rehabilitation are unknown. This two-group intervention study aimed to investigate the effects of two rehabilitation programs on the recovery of lumbo-pelvic musculature following prolonged bed rest. 24 subjects underwent 60 days of head down tilt bed rest as part of the 2nd Berlin BedRest Study (BBR2-2). After bed rest, they underwent one of two exercise programs, trunk flexor and general strength (TFS) training or specific motor control (SMC) training. Magnetic resonance imaging of the lumbo-pelvic region was conducted at the start and end of bed rest and during the recovery period (14 and 90 days after re-ambulation). Cross-sectional areas (CSAs) of the multifidus, psoas, lumbar erector spinae and quadratus lumborum muscles were measured from L1 to L5. Morphological changes including disc volume, spinal length, lordosis angle and disc height were also measured. Both exercise programs restored the multifidus muscle to pre-bed-rest size, but further increases in psoas muscle size were seen in the TFS group up to 14 days after bed rest. There was no significant difference in the number of low back pain reports for the two rehabilitation groups (p=.59). The TFS program resulted in greater decreases in disc volume and anterior disc height. The SMC training program may be preferable to TFS training after bed rest as it restored the CSA of the multifidus muscle without generating potentially harmful compressive forces through the spine.

A magnetic resonance imaging investigation of the transversus abdominis muscle during drawing-in of the abdominal wall in elite Australian Football League players with and without low back pain.

STUDY DESIGN: Single-blinded quasi-experimental study. OBJECTIVE: To investigate the ability of elite football players with and without low back pain (LBP) to voluntarily draw-in the abdominal wall. BACKGROUND: While there has been considerable debate regarding the contribution of the transversus abdominis (TrA) muscle to control the lumbar spine and pelvis, there is evidence that retraining motor control of the deep trunk muscles is commensurate with decreases in LBP. Magnetic resonance imaging (MRI) has been used to assess the TrA muscle during the draw-in maneuver, with the contraction of the TrA muscle reducing the circumference of the trunk. Impairments in performance of the draw-in maneuver have been shown in people with LBP. METHODS: Forty-three elite players from a team in the Australian Football League were allocated to 3 groups: those with "no LBP," "a history of LBP but no current LBP," or "current LBP." MRI was used to image the cross-sectional area (CSA) of the trunk at the level of the L3-4 disc at the start and end of the draw-in maneuver. RESULTS: There was a significant decrease in the CSA of the trunk with the performance of the draw-in maneuver (P<.001). Subjects in the "no LBP" group were better able to "draw-in" the abdominal wall than subjects with current LBP (P = .015). CONCLUSIONS: This study provides evidence of an altered ability to draw-in the abdominal wall in footballers with current LBP. Retraining contraction of the TrA muscle may constitute one part of an exercise-therapy approach for athletes with current LBP.

Effect of stabilization training on multifidus muscle cross-sectional area among young elite cricketers with low back pain.

STUDY DESIGN: A single-blinded, pretreatment-posttreatment assessment. OBJECTIVES: To investigate, using ultrasound imaging, the cross-sectional area (CSA) of the lumbar multifidus muscle at 4 vertebral levels (L2, L3, L4, L5) in elite cricketers with and without low back pain (LBP) and (2) to document the effect of a staged stabilization training program on multifidus muscle CSA. BACKGROUND: Despite high fitness levels and often intensive strength training programs, athletes still suffer LBP. The incidence of LBP among Australian cricketers is 8% and as high as 14% among fast bowlers. Previous researchers have found that the multifidus muscle contributes to segmental stability of the lumbopelvic region; however, the CSA of this muscle has not been previously assessed in elite cricketers. METHODS AND MEASURES: CSAs of the multifidus muscles were assessed at rest on the left and right sides for 4 vertebral levels at the start and completion of a 13-week cricket training camp. Participants who reported current or previous LBP were placed in a rehabilitation group. The stabilization program involved voluntary contraction of the multifidus, transversus abdominis, and pelvic floor muscles, with real-time feedback from rehabilitative ultrasound imaging (RUSI), progressed from non-weight-bearing to weight-bearing positions and movement training. Pain scores (using a visual analogue scale) were also collected from those with LBP. RESULTS: The CSAs of the multifidus muscles at the L5 vertebral level increased for the 7 cricketers with LBP who received the stabilization training, compared with the 14 cricketers without LBP who did not receive rehabilitation (P = .004). In addition, the amount of muscle asymmetry among those with LBP significantly decreased (P = .029) and became comparable to cricketers without LBP. These effects were not evident for the L2, L3, and L4 vertebral levels. There was also a 50% decrease in the mean reported pain level among the cricketers with LBP. CONCLUSION: Multifidus muscle atrophy can exist in highly active, elite athletes with LBP. Specific retraining resulted in an improvement in multifidus muscle CSA and this was concomitant with a decrease in pain. LEVEL OF EVIDENCE: Therapy, level 2b.

Lateral positioning of ventilated intensive care patients: a study of oxygenation, respiratory mechanics, hemodynamics, and adverse events.

OBJECTIVES: To investigate the effect of 90 degrees lateral positioning on oxygenation, respiratory mechanics, and hemodynamics in ventilated intensive care patients. METHODS: Thirty-four subjects (mean age = 46.1 +/- 17.3 years) with no, unilateral, or bilateral pulmonary infiltrates on chest radiograph participated. Arterial blood gas, respiratory mechanic, and hemodynamic data were analyzed at the supine starting position (T0), then 30 minutes and 2 hours into the lateral turn (T30 and T120, respectively) and 30 minutes post return to the supine position (T150). RESULTS: No difference was found in PaO(2)/FiO(2) due to positioning patients from supine to lateral (P = .15) regardless of the underlying lung pathology. Dynamic compliance decreased during lateral positioning, particularly in the subjects with no lung pathology (T0 = 56 +/- 18.6 > (T30 = 49.9 +/- 18; T120 = 49.2 +/- 17) L/cmH(2)0, P < .01) or unilateral lung pathology (T0 = 41.4 +/- 11.2 > (T30 = 36.6 +/- 8.8; T120 = 37.3 +/- 9.5) L/cmH(2)0, P < .01). Blood pressure and heart rate were unaffected, but cardiac index significantly increased at T30 (T0 = 3.7 +/- 1.2, T30 = 4.8 +/- 1.3 L/min/m(2), P < .01). While the incidence of adverse events was high (21%), they were primarily minor and transient. CONCLUSIONS: In this heterogeneous population, lateral positioning had no beneficial effect on gas exchange. However, in ventilated patients who were hemodynamically stable, it was well tolerated and not associated with significant serious adverse events.

Intrarater and interrater reliability of assessment of lumbar multifidus muscle thickness using rehabilitative ultrasound imaging.

STUDY DESIGN: Within-session intrarater and interrater reliability study. OBJECTIVE: To establish the intrarater and interrater reliability of thickness measurements of the multifidus muscle in a parasagittal plane, conducted by an experienced ultrasound operator and a novice assessor. BACKGROUND: There is considerable evidence for the important role of the multifidus muscle in segmental stabilization of the lumbar spine. The cross-sectional area of the multifidus muscle has been assessed in healthy subjects and patients with low back pain using real-time ultrasound imaging. However, few studies have measured the thickness of the multifidus muscle using a parasagittal view. METHODS AND MEASURES: The thickness of the multifidus muscle was measured at rest, using real-time ultrasound imaging, in 10 subjects without a history of low back pain, at the levels of the L2-3 and L4-5 zygapophyseal joints. The measure was carried out 3 times at each level by 2 assessors (1 experienced, 1 novice). Intrarater (model 3) and interrater (model 2) reliability was assessed by calculation of an F statistic (analysis of variance), the intraclass correlation coefficient (ICC), and the standard error of measurement (SEM). RESULTS: On the basis of an average of 3 trials, the 2 operators showed very high interrater agreement on the measurement of thicknesses at the L2-3 level (ICC2,3 = 0.96; 95% CI: 0.84 to 0.99) and the L4-5 vertebral level (ICC2,3 = 0.97; 95% CI: 0.87 to 0.99), with no systematic differences in muscle size across operators (P > .05). Interrater reliability was relatively lower for the L2-3 level (ICC2,1 = 0.85; 95% CI: 0.51 to 0.96) than the L4-5 level (ICC2,1 = 0.87; 95% CI: 0.52 to 0.97) when a single trial per rater was used, but these values still indicated a high level of agreement. In addition, the novice and experienced operator produced reliable intrarater measurements at L2-3 (ICC3,1 = 0.89; 95% CI: 0.72 to 0.97 and 0.94; 95% CI: 0.86 to 0.99) and at L4-5 (ICC3,1 = 0.88; 95% CI: 0.68 to 0.97 and 0.95; 95% CI: 0.86 to 0.99), with no systematic differences in muscle size across trials (P > .05). The consistently low SEM values also indicate low measurement error. CONCLUSION: A novice and an experienced assessor were both able to reliably perform this measure at rest for 2 vertebral levels using real-time ultrasound imaging. An average of 3 trials produced higher interrater reliability scores, though using a single trial per rater was also reliable.

Ultrasound imaging assessment of abdominal muscle function during drawing-in of the abdominal wall: an intrarater reliability study.

STUDY DESIGN: Test-retest intrarater reliability study. OBJECTIVE: To examine reliability of abdominal musculature measurements across a broad range of conditions for a physical therapist newly trained in assessment using rehabilitative ultrasound imaging (RUSI). BACKGROUND: RUSI has previously been used to assess abdominal muscle function during a drawing-in maneuver of the anterior abdominal wall, and measurements conducted by an experienced assessor have been validated by comparison with magnetic resonance imaging. Few studies have examined the reliability of less experienced operators, and only in isolated measurement conditions. METHODS AND MEASURES: Nineteen subjects (11 female, 8 male) without a history of low back pain performed the abdominal drawing-in maneuver in a supine hook-lying position. RUSI was used bilaterally to assess the thickness of the internal oblique (IO) and transversus abdominis (TrA) muscles at rest and on contraction, as well as changes in the length of the TrA muscle (indicated by slide of the anterior abdominal fascia). The reliability of a novice rater who received 8 hours of training was examined (a) across 3 measurements of the same ultrasound image, (b) across 3 separate ultrasound images (averaged for days and sides of abdomen), and (c) across 2 days (averaged for images and sides). RESULTS: Reliability of assessing muscle thickness was very high across 3 measurements of the sale image (intrarater correlation coefficients [ICC3.1] were all greater than 0.97), fair to high across 3 images (ICC(3,4) = 0.62-0.82), and fair to high across 2 days (ICC(3,6) = 0.63-0.85). Reliability of measuring the slide of the anterior abdominal fascia was very high across measurements from the same image (ICC(3,1) = 0.98) but very low across images (ICC(3,4) = 0.44) and across 2 days (ICC(3,6) = 0.36). CONCLUSIONS: High reliability of a novice rater was demonstrated for some measurement conditions. Measures of reliability for recapturing the image and repetition across days ranged from low to high. Inconsistencies in the pattern of results suggest that for a novice assessor using RUSI, training should be performed and reliability assessed for each abdominal muscle and measurement condition intended to be used for research and clinical practice.

Determinants of stages of smoking uptake among secondary school students.

With the uptake of cigarette smoking hypothesised to occur through a series of contemplation and action stages, we sought to investigate what factors are associated with the contemplation of smoking among secondary school students in Queensland, Australia. A series of four cross-sectional surveys were conducted among secondary schools in Queensland in 1993, 1996, 1999 and 2002. Respondents (n = 9993) were asked about the stages of smoking. Nearly half (43%) of secondary school students reported some contemplation of smoking. Increased levels of smoking contemplation were observed among females, earlier survey years, Junior level students, students with average or below average scholastic ability, those prepared to go out with a smoker, those with recent alcohol experience, those who had influenced other students to smoke or had not discouraged other students smoking. The results of this study provide further information about the factors relevant to stages of smoking uptake among secondary school students and the influence that students may have on their peers.

Sitting posture affects pelvic floor muscle activity in parous women: an observational study.

QUESTION: Do different sitting postures require different levels of pelvic floor and abdominal muscle activity in healthy women? DESIGN: Observational study. PARTICIPANTS: Eight parous women with no pelvic floor dysfunction. OUTCOME MEASURES: Bilateral activity of pelvic floor muscles (assessed vaginally) and two abdominal muscles, obliquus internus abdominis and obliquus externus abdominis, during three sitting postures. RESULTS: There was a significant increase in pelvic floor muscle activity from slump supported sitting (mean 7.2% maximal voluntary contraction, SD 4.8) to both upright unsupported sitting (mean 12.6% maximal voluntary contraction, SD 7.8) (p = 0.01) and very tall unsupported sitting (mean 24.3% maximal voluntary contraction, SD 14.2) (p = 0.004). Activity in both abdominal muscles also increased but did not reach statistical significance. CONCLUSION: Both unsupported sitting postures require greater pelvic floor muscle activity than the supported sitting posture.

Positioning practices for ventilated intensive care patients: current practice, indications and contraindications.

To investigate the process of providing patient positioning in intensive care units (ICUs), a self-reported survey was distributed to a senior physiotherapist and a nurse in each of the 38 Level 3 Australian ICUs. The survey explored the rationales, aims, type, frequency and duration of directed patient positioning used, and perceived risks that may impede the implementation of an effective positioning regime. The response rate was 93%. Fifty nine respondents (83%) agreed that there is an accepted standard of care for the duration of a position change with ventilated patients. Of these respondents, 51 (86%) agreed that the standard is to turn patients every 2 hours, but this was only achievable "more than 50% of the time" in 47% (n=34) of ICUs. Educational and environmental issues were found to impact on positioning practices. Semi-recumbent and full side-lie positions were recommended in the management of a range of patient conditions. However, full side-lie was less commonly used than supine positioning. The prone and head down tilt positions were the least frequently utilised. Levels of agreement for precautions and contraindications to positioning patients into full side-lie and sitting were high. We conclude that, in Australia, experienced ICU physiotherapy and nursing staff are aware of evidence-based positioning practices and agree on indications and potential risk factors associated with positioning. However, educational and environmental resources are needed to improve the frequency and type of positioning used. Results from this survey can now be incorporated into educational tools to facilitate the safe use of positioning.

The effect of motor control training on abdominal muscle contraction during simulated weight bearing in elite cricketers.

OBJECTIVES: To investigate whether motor control training alters automatic contraction of abdominal muscles in elite cricketers with low back pain (LBP) during performance of a simulated unilateral weight-bearing task. DESIGN: Clinical trial. METHODS: 26 male elite-cricketers attended a 13-week cricket training camp. Prior to the camp, participants were allocated to a LBP or asymptomatic group. Real-time ultrasound imaging was used to assess automatic abdominal muscle response to axial loading. During the camp, the LBP group performed a staged motor control training program. Following the camp, the automatic response of the abdominal muscles was re-assessed. RESULTS: At pre-camp assessment, when participants were axially loaded with 25% of their own bodyweight, the LBP group showed a 15.5% thicker internal oblique (IO) muscle compared to the asymptomatic group (p = 0.009). The post-camp assessment showed that participants in the LBP group demonstrated less contraction of the IO muscle in response to axial loading compared with the asymptomatic group. A trend was found in the automatic recruitment pattern of the transversus abdominis (p = 0.08). CONCLUSIONS: Motor control training normalized excessive contraction of abdominal muscles in response to a low load task. This may be a useful strategy for rehabilitation of cricketers with LBP.

Suntans and sun protection in Australian teen media: 1999 to 2000.

In this study, the portrayal of tanned skin and sun protection in magazines, television programs, and movies popular with Australian adolescents were analyzed. Images of models in magazines (n = 1,791), regular/supporting characters in television programs (n = 867), and regular/supporting characters in cinema movies (n = 2,836)for the 12-month period August 1999 to July 2000 were coded and analyzed. A light tan was the most predominant tan level, and protective clothing was the most common sun protection measure displayed across all forms of media. There were significant associations between gender and tan levels in the television and movie samples. Although it is important to monitor the portrayal of tan levels and sun protection measures in media targeting adolescents, overall, the authors' findings revealed a media environment generally supportive of sun protection objectives.

Guaiac versus immunochemical tests: faecal occult blood test screening for colorectal cancer in a rural community.

OBJECTIVE: To describe patient participation and clinical performance in a colorectal cancer (CRC) screening program utilising faecal occult blood test (FOBT). METHODS: A community-based intervention was conducted in a small, rural community in north Queensland, 2000/01. One of two FOBT kits--guaiac (Hemoccult-II) or immunochemical (!nform)--was assigned by general practice and mailed to participants (3,358 patients aged 50-74 years listed with the local practices). RESULTS: Overall participation in FOBT screening was 36.3%. Participation was higher with the immunochemical kit than the guaiac kit (OR=1.9, 95% CI 1.6-2.2). Women were more likely to comply with testing than men (OR=1.4, 95% CI 1.2-1.7), and people in their 60s were less likely to participate than those 70-74 years (OR=0.8, 95% CI 0.6-0.9). The positivity rate was higher for the immunochemical (9.5%) than the guaiac (3.9%) test (chi2=9.2, p=0.002), with positive predictive values for cancer or adenoma of advanced pathology of 37.8% (95% CI 28.1-48.6) for !nform and 40.0% (95% CI 16.8-68.7) for Hemoccult-II. Colonoscopy follow-up was 94.8% with a medical complication rate of 2-3%. CONCLUSIONS: An immunochemical FOBT enhanced participation. Higher positivity rates for this kit did not translate into higher false-positive rates, and both test types resulted in a high yield of neoplasia. IMPLICATIONS: In addition to type of FOBT, the ultimate success of a population-based screening program for CRC using FOBT will depend on appropriate education of health professionals and the public as well as significant investment in medical infrastructure for colonoscopy follow-up.

The effect of weight-bearing exercise with low frequency, whole body vibration on lumbosacral proprioception: a pilot study on normal subjects.

Patients with low back pain (LBP) often present with impaired proprioception of the lumbopelvic region. For this reason, proprioception training usually forms part of the rehabilitation protocols. New exercise equipment that produces whole body, low frequency vibration (WBV) has been developed to improve muscle function, and reportedly improves proprioception. The aim of this pilot study was to investigate whether weightbearing exercise given in conjunction with WBV would affect lumbosacral position sense in healthy individuals. For this purpose, twenty-five young individuals with no LBP were assigned randomly to an experimental or control group. The experimental group received WBV for five minutes while holding a static, semi-squat position. The control group adopted the same weightbearing position for equal time but received no vibration. A two-dimensional motion analysis system measured the repositioning accuracy of pelvic tilting in standing. The experimental (WBV) group demonstrated a significant improvement in repositioning accuracy over time (mean 0.78 degrees) representing 39% improvement. It was concluded that WBV may induce improvements in lumbosacral repositioning accuracy when combined with a weightbearing exercise. Future studies with WBV should focus on evaluating its effects with different types of exercise, the exercise time needed for optimal outcomes, and the effects on proprioception deficits in LBP patients.

Community perceptions of adequate levels and reasons for skin protection.

In this study the authors addressed whether or not community members use relevant risk factors to determine an appropriate level of skin protection behavior in the prevention of skin cancer. The authors conducted a postal survey with a community sample of 3,600 Queensland residents that they randomly selected from the Commonwealth electoral roll. The predictors of "perceptions of doing enough skin protection" included intrapersonal, social, and attitudinal influences. People protected themselves from the sun primarily out of a desire for future good health and on other occasions did not protect themselves from the sun because they were not out there long enough to get burnt. The predictors of perceptions of doing enough skin protection indicated that participants were aware of relevant risk factors. The main reasons that people protect themselves from the sun suggest that they are acting on many health promotion messages. However, skin cancer prevention programs need to move beyond increasing awareness and knowledge of the disease to providing a supportive environment and enhancing individual skills. Health promotion campaigns could reinforce appropriate risk assessment and shape an individual's decision about how much sun protection is needed.

Clinical diagnosis and management of suspicious pigmented skin lesions--a survey of GPs.

BACKGROUND: The ability of general practitioners to make important clinical decisions about the diagnosis and management of skin lesions is poorly understood. METHODS: A questionnaire on the diagnosis and management of eight photographed skin lesions was sent to 150 GPs in southeast Queensland. RESULTS: The questionnaire was completed by 114 GPs (response rate 77%). General practitioners' provisional diagnoses and management of photographed skin lesions were mostly or always correct, and there was general high consistency between diagnosis and intended management. Pigmented seborrhoeic keratoses were the most difficult lesions for GPs to diagnose correctly. Whether a lesion was different to usual moles appears to have the strongest association with clinical diagnosis. DISCUSSION: The high ability of GPs as measured in this artificial study is encouraging. The strong association between identifying moles that appear different to usual and correct clinical diagnoses suggest that unless GPs can increase the number of skin lesions they see as part of their typical workload, their clinical ability may not increase further.

The relationship between the piriformis muscle, low back pain, lower limb injuries and motor control training among elite football players.

OBJECTIVES: Australian Football League (AFL) players have a high incidence of back injuries. Motor control training to increase lumbopelvic neuromuscular control has been effective in reducing low back pain (LBP) and lower limb injuries in elite athletes. Control of pelvic and femoral alignment during functional activity involves the piriformis muscle. This study investigated (a) the effect of motor control training on piriformis muscle size in AFL players, with and without LBP, during the playing season, and (b) whether there is a relationship between lower limb injury and piriformis muscle size. DESIGN: Stepped-wedge intervention. METHODS: 46 AFL players participated in a motor control training programme consisting of two 30min sessions per week over 7-8 weeks, delivered across the season as a randomised 3 group single-blinded stepped-wedge design. Assessment of piriformis muscle cross-sectional area (CSA) involved magnetic resonance imaging (MRI) at 3 time points during the season. Assessment of LBP consisted of player interview and physical examination. Injury data were obtained from club records. RESULTS: An interaction effect for Time, Intervention Group and LBP group (F=3.7, p=0.03) was found. Piriformis muscle CSA showed significant increases between Times 1 and 2 (F=4.24, p=0.046), and Times 2 and 3 (F=8.59, p=0.006). Players with a smaller increase in piriformis muscle CSA across the season had higher odds of sustaining an injury (OR=1.08). CONCLUSIONS: Piriformis muscle size increases across the season in elite AFL players and is affected by the presence of LBP and lower limb injury. Motor control training positively affects piriformis muscle size in players with LBP.

Dissemination of an efficacious antenatal smoking cessation program in public hospitals in Australia: a randomized controlled trial.

This study investigated the impact of a behaviorally based intervention designed to increase the number of hospitals that routinely provide effective smoking cessation programs for pregnant women. In Queensland, Australia, 70 publicly funded hospitals were matched on numbers of births and maternal socioeconomic status and randomly allocated to an awareness-only intervention group or a behaviorally based intervention group. Success was defined as the routine offer of an evidence-based smoking cessation program to at least 80% of the pregnant clients who smoke. At 1 month, 65% of the behaviorally based intervention hospitals agreed to provide materials about smoking cessation programs for their antenatal patients, compared with 3% of the awareness-only hospitals. After 1 year, 43% of the intervention hospitals still provided the material, compared with 9% of the awareness-only hospitals. These findings show that a brief intervention to hospitals can encourage antenatal staff to provide smoking cessation materials to pregnant women.

Knowledge, attitude and intentions related to colorectal cancer screening using faecal occult blood tests in a rural Australian population.

A telephone survey with 604 men and women without history of colorectal cancer (CRC) (age 50-74 years) explored knowledge of, attitudes toward, and intention to screen for CRC using faecal occult blood tests (FOBT) in a rural Australian population. Overall, 53% intended to participate in and 86% would follow a doctor's recommendation for FOBT screening. In contrast, only 18% had ever had a FOBT, and fewer than 60% of those with high-risk family history had undergone appropriate screening for CRC. Prior use of FOBT (OR=3.2), high perceived susceptibility to CRC (OR=2.4), belief in the importance of screening despite the absence of symptoms (OR=2.1) were positively and older age (OR = 0.5) was negatively related to screening intention in multivariate logistic regression analysis. A doctor's recommendation improved screening intention among those who never tested for CRC before but believe in the importance of early treatment. This study highlights the lack of compliance with standard CRC screening recommendations in Australia and provides evidence for the importance of continued educational efforts, with the particular emphasis on older adults and the medical community.

Can motor control training lower the risk of injury for professional football players?

PURPOSE: Among injuries reported by the Australian Football League (AFL), lower limb injuries have shown the highest incidence and prevalence rates. Deficits in the muscles of the lumbopelvic region, such as a smaller size of multifidus (MF) muscle, have been related to the occurrence of lower limb injuries in the preseason in AFL players. Motor control training programs have been effective in restoring the size and control of the MF muscle, but the relationship between motor control training and occurrence of injuries has not been extensively examined. METHODS: This pre- and postintervention trial was delivered during the playing season as a panel design with three groups. The motor control program involved voluntary contractions of the MF, transversus abdominis, and pelvic floor muscles while receiving feedback from ultrasound imaging and progressed into a functional rehabilitation program. Assessments of muscle size and function were performed using magnetic resonance imaging and included the measurement of cross-sectional areas of MF, psoas, and quadratus lumborum muscles and the change in trunk cross-sectional area due to voluntarily contracting the transversus abdominis muscle. Injury data were obtained from club records. Informed consent was obtained from all study participants. RESULTS: A smaller size of the MF muscle (odds ratio [OR] = 2.38) or quadratus lumborum muscle (OR = 2.17) was predictive of lower limb injury in the playing season. At the time point when one group of players had not received the intervention (n = 14), comparisons were made with the combined groups who had received the intervention (n = 32). The risk of sustaining a severe injury was lower for those players who received the motor control intervention (OR = 0.09). CONCLUSION: Although there are many factors associated with injuries in AFL, motor control training may provide a useful addition to strategies aimed at reducing lower limb injuries.

Repeated-sprint ability and team selection in Australian football league players.

PURPOSE: To investigate the relationship between selected physical capacities and repeated-sprint performance of Australian Football League (AFL) players and to determine which physical capacities contributed to being selected for the first competition game. METHODS: Sum of skinfolds, 40-m sprint (with 10-, 20-, 30-, and 40-m splits), repeated-sprint ability (6 × 30-m sprints), and 3-km-run time were measured during the preseason in 20 AFL players. The physical qualities of players selected to play the first match of the season and those not selected were compared. Pearson correlation coefficients were used to determine the relationship among variables, and a regression analysis identified variables significantly related to repeated-sprint performance. RESULTS: In the regression analysis, maximum velocity was the best predictor of repeated-sprint time, with 3-km-run time also contributing significantly to the predictive model. Sum of skinfolds was significantly correlated with 10-m (r = .61, P < .01) and 30-m (r = .53, P < .05) sprint times. A 2.6% ± 2.1% difference in repeated-sprint time (P < .05, ES = 0.88 ± 0.72) was observed between those selected (25.26 ± 0.55 s) and not selected (25.82 ± 0.80 s) for the first game of the season. CONCLUSIONS: The findings indicate that maximum-velocity training using intervals of 30-40 m may contribute more to improving repeated-sprint performance in AFL players than short 10- to 20-m intervals from standing starts. Further research is warranted to establish the relative importance of endurance training for improving repeated-sprint performance in AFL football.