Christopher J. Durall

The effects of preseason trunk muscle training on low-back pain occurrence in women collegiate gymnasts.

Durall, CJ, Udermann, BE, Johansen, DR, Gibson, B, Reineke, DM, and Reuteman, P. The effects of preseason trunk muscle training on low-back pain occurrence in women collegiate gymnasts. J Strength Cond Res 23(1): 86-92, 2009-Low-back pain (LBP) in women gymnasts is relatively common. This investigation was performed to evaluate the effects of a preseason training program for the trunk extensor, lateral flexor, and flexor muscles on LBP occurrence during the subsequent competitive season. The training group consisted of 15 collegiate women gymnasts. The control group consisted of 15 nonathlete collegiate women. Pre- and posttesting for all participants consisted of static endurance tests for the trunk extensors, lateral flexors, and flexors. After pretesting, the training group completed 10 weeks of biweekly training consisting of non-foot-supported back extensions and side bridges, in addition to their usual trunk flexor exercises. The control group did not perform any specialized trunk muscle training. Mean improvements in trunk endurance, based on multivariate analysis of variance at the 5% level of significance, were significantly greater in the training group than in the control group. Mean improvements in endurance in the training group were 47 seconds for the lateral trunk flexors, 34 seconds for the trunk extensors, and 80 seconds for the trunk flexors. During the subsequent gymnastics season, none of the gymnasts reported new episodes of LBP. One gymnast with chronic LBP reported a recurrence of LBP during the season. None of the gymnasts reported that the training program adversely affected their gymnastic performance. These data suggest that training the trunk musculature twice per week during a 10-week period with a relatively simple floor exercise protocol was an effective stimulus to improve trunk endurance measures. It is encouraging that none of the gymnasts reported new episodes of LBP during the subsequent competitive gymnastics season.

Ankle bracing, plantar-flexion angle, and ankle muscle latencies during inversion stress in healthy participants.

CONTEXT Ankle braces may enhance ankle joint proprioception, which in turn may affect reflexive ankle muscle activity during a perturbation. Despite the common occurrence of plantar-flexion inversion ankle injuries, authors of previous studies of ankle muscle latencies have focused on inversion stresses only. OBJECTIVE To examine the latency of the peroneus longus (PL), peroneus brevis (PB), and tibialis anterior (TA) muscles in response to various degrees of combined plantar-flexion and inversion stresses in braced and unbraced asymptomatic ankles. DESIGN Repeated measures. SETTING University biomechanics laboratory. PATIENTS OR OTHER PARTICIPANTS Twenty-eight healthy females and 12 healthy males (n = 40: mean age = 23.63 years, range = 19 to 30 years; height = 172.75 +/- 7.96 cm; mass = 65.53 +/- 12.0 kg). INTERVENTION(S) Participants were tested under 2 conditions: wearing and not wearing an Active Ankle T1 brace while dropping from a custom-made platform into 10 degrees , 20 degrees , and 30 degrees of plantar flexion and 30 degrees of inversion. MAIN OUTCOME MEASURE(S) The time between platform drop and the onset of PL, PB, and TA electromyographic activity was measured to determine latencies. We calculated a series of 2-way analyses of variance to determine if latencies were different between the conditions (braced and unbraced) and among the plantar-flexion angles (alpha = .05). RESULTS No interaction was found between condition and plantar-flexion angle. No significant main effects were found for condition or plantar-flexion angle. Overall means for braced and unbraced conditions were not significantly different for each muscle tested. Overall means for angle for the PL, PB, and TA were not significantly different. CONCLUSIONS Reflexive activity of the PL, PB, or TA was unaffected by the amount of plantar flexion or by wearing an Active Ankle T1 brace during an unanticipated plantar-flexion inversion perturbation.

The Accuracy of the Functional Movement Screen to Identify Individuals with an Elevated Risk of Musculoskeletal Injury

CLINICAL SCENARIO Injuries are somewhat commonplace in highly active populations. One strategy for reducing injuries is to identify individuals with an elevated injury risk before participation so that remediative interventions can be provided. Preparticipation screenings have traditionally entailed strength and flexibility measures thought to be indicative of inflated injury risk. Some researchers, however, have suggested that functional movements/tasks should be assessed to help identify individuals with a high risk of future injury. One assessment tool used for this purpose is the Functional Movement Screen (FMS). The FMS generates a numeric score based on performance attributes during 7 dynamic tasks; this score is purported to reflect future injury risk. Expanding interest in the FMS has led researchers to investigate how accurately it can identify individuals with an increased risk of injury. FOCUSED CLINICAL QUESTION Can the Functional Movement Screen accurately identify highly active individuals with an elevated risk of injury?

A comparison of two isometric tests of trunk flexor endurance.

Abstract Durall, CJ, Greene, PF, and Kernozek, TW. A comparison of two isometric tests of trunk flexor endurance. J Strength Cond Res 26(7): 1939–1944, 2012—This study was performed to determine the test-retest reliability and the relationship between 2 tests of trunk flexor muscular endurance—a prone bridge and a modified V-sit. Hold times (in seconds) were measured on 60 healthy volunteers from a University community (17 men, 43 women). Both tests were performed at 1-week intervals. The test-retest reliability of each test was assessed with a subgroup of 10 participants during 3 additional testing sessions at 1-week intervals. One examiner collected all data. Intraclass correlation coefficients (2,1) with the prone bridge were 0.95 and 0.71 with the modified V-sit. The mean hold time was 92.8 ± 44.4 seconds during the prone bridge and 141.7 ± 104.1 seconds during the modified V-sit. Pearsons correlation coefficients between the 2 tests ranged from r = 0.52 (men + women) to r = 0.87 (men only). Intersession reliability with a single examiner was higher with the prone bridge compared with that in the modified V-sit. Modifications to the V-sit resulted in a lower test-retest reliability than was previously reported. Correlations between prone bridge and modified V-sit test scores were low, which may be attributable to the differences in the level of trunk flexor muscle activation between the tests.

Does Talocrural Joint-Thrust Manipulation Improve Outcomes After Inversion Ankle Sprain?

Clinical Scenario: Ankle sprains account for roughly 10% of sport-related injuries in the active population. The majority of these injuries occur from excessive ankle inversion, leading to lateral ligamentous injury. In addition to pain and swelling, limitations in ankle range of motion (ROM) and self-reported function are common findings. These limitations are thought to be due in part to loss of mobility in the talocrural joint. Accordingly, some investigators have reported using high-velocity, low-amplitude thrust-manipulation techniques directed at the talocrural joint to address deficits in dorsiflexion (DF) ROM and function. This review was conducted to ascertain the impact of talocrural joint-thrust manipulation (TJM) on DF ROM, self-reported function, and pain in patients with a history of ankle sprain. Focused Clinical Question: In patients with a history of inversion ankle sprain, does TJM improve outcomes in DF ROM, self-reported function, and/or pain?