Influence of Posture-Cuing Shirt on Tennis Serve Kinematics in Division III Tennis Players.

OBJECTIVE: The purpose of this study was to evaluate the influence of a posture-cuing shirt on internal rotation velocity of the shoulder during a tennis swing and to determine this influence on shoulder external rotation position. METHODS: Nine healthy competitive college tennis players from a Division III college participated in this study. High-speed motion capture allowed for 3-dimensional analysis of shoulder kinematics during a tennis serve. Two conditions were evaluated while the athletes performed a high-velocity tennis serve: a standard tennis shirt and a posture-cuing shirt. RESULTS: Shoulder internal rotation velocity increased when wearing the posture-cuing shirt. Peak internal rotation velocity increased from 960.61°/s ± 93.24°/s to 1217.96°/s ± 155.01°/s (t = -1.76, P = .058). Internal rotation velocity at the time of impact increased from 765.18°/s ± 95.48°/s to 900.54°/s ± 105.33°/s (t = -1.50, P = .086). Shoulder maximum external rotation did not differ between the 2 conditions, at 172.00° ± 2.92° and 170.89° ± 3.70° (t = 0.325, P = .754). CONCLUSIONS: Wearing a posture-cuing shirt may possibly alter shoulder kinematics during an overhead sport activity such as tennis. Internal rotation velocity seemed to improve while wearing this shirt, although shoulder external rotation position did not change. It is not known if these improvements can influence injury risk.

Self-reported smoking and musculoskeletal overuse injury among male and female U.S. Marine Corps recruits.

The association between self-reported smoking and overuse injury in a cohort of young men (n = 900) and women (n = 597) undergoing 12 weeks of standardized military instruction, after adjustment for physical activity, health history, and incoming fitness tests was examined. The outcome includes all International Classification of Diseases, 9th Revision codes related to injuries resulting from cumulative microtrauma (overuse injuries). The short survey asked about the subject's demographics, smoking habits, prior injuries sustained, physical activity level, self-perceived fitness, and (for women) menstrual history. From the survey, 4 questions established smoking behavior: smoked at least 100 cigarettes in lifetime, age smoked a whole cigarette for the first time, how many cigarettes smoked during the last 30 days, and how many cigarettes smoked per day during the last 30 days. None of the adjusted hazard ratios for the smoking questions were associated with an increased risk of overuse injury for either sex. Furthermore, this study did not find a significant association with respect to smoking and all injuries in either men or women. In conclusion, smoking does not appear to be an independent risk factor for overuse injury in either young men or women during 12 weeks of standardized military instruction.

Perceived influence of a compression, posture-cueing shirt on cyclists' ride experience and post-ride recovery.

OBJECTIVE: The purpose of this study was to evaluate the opinions of experienced cyclists on perceived influence of a posture-cueing shirt with compressive properties on their comfort and recovery. METHODS: Twenty experienced cyclists wore a compressive shirt during rides and as a postride recovery shirt; cyclists rated their perceived experiences during rides and recovery. They completed 2 separate questionnaires specific to riding or recovery; scores ranged from - 3.0 (negative influence) to + 3.0 (positive influence), addressing posture, discomfort, breathing, and recovery. Data analysis included frequencies and t tests to compare groups. RESULTS: Cyclists completed 53 rides, averaging 95.48 km (SD = 31.72 km), wearing the shirt and reported a perceived benefit (mean score = 1.17, SD = 0.25). For their postride recovery perceptions, scores averaged 1.99 (SD = 0.48) for perceived benefits for recovery. No differences in scores were identified between male and female cyclists during rides (t = - 0.28, P > .05); however, female riders perceived greater benefit during recovery (t = - 2.24, P < .05). There were no correlations with scores and cyclist age, experience, or ride distances during rides or recovery (r = 0.02-0.35). CONCLUSION: A posture-cueing, compressive shirt was rated to have a perceived benefit by experienced cyclists for riding posture, postride posture, spine discomfort, and postride recovery. This study did not evaluate physical or physiologic variables to confirm these perceptions.

The association of self-reported measures with poor training outcomes among male and female U.S. Navy recruits.

This prospective study evaluated the association of self-reported health habits and behaviors in 2,930 Navy recruits with poor training outcomes, defined as graduating late or separating from training. Although 17% of the men and 21% of the women had a poor training outcome, results suggest that some self-reported measures were associated with poor training outcomes. Men who did not run or jog at least 1 month before basic training or had a previous lower limb injury without complete recovery and women reporting the same or less physical activity compared with their same-age counterparts were more likely to have a poor training outcome. An important first step in decreasing poor training outcomes is encouraging incoming recruits to participate in physical activity and taking steps to identify and rehabilitate recruits who are not completely healed from a lower limb musculoskeletal injury before reporting to basic training.

Rating scale analysis and psychometric properties of the Caregiver Self-Efficacy Scale for Transfers.

Parents and caregivers faced with the challenges of transferring children with disability are at risk of musculoskeletal injuries and/or emotional stress. The Caregiver Self-Efficacy Scale for Transfers (CSEST) is a 14-item questionnaire that measures self-efficacy for transferring under common conditions. The CSEST yields reliable data and valid inferences; however, its rating scale structure has not been evaluated for utility. The aims of this study were to evaluate the category response structure of the CSEST, test the utility of a revised rating scale structure, and confirm its psychometric properties. The Rasch Measurement Model was used for all analyses. Subjects included 175 adult caregivers recruited from multiple communities. Results confirm that a revised five-category rating scale structure yields reliable data and valid inferences. Given the relationship between self-efficacy and risk of physical and/or emotional stress, measuring parental self-efficacy for transfers is a proactive process in rehabilitation.

Shoulder- and back-muscle activation during shoulder abduction and flexion using a Bodyblade Pro versus dumbbells.

CONTEXT: The Bodyblade Pro is used for shoulder rehabilitation after injury. Resistance is provided by blade Oscillations-faster oscillations or higher speeds correspond to greater resistance. However, research supporting the Bodyblade Pro's use is scarce, particularly in comparison with dumbbell training. OBJECTIVE: To compare muscle activity, using electromyography (EMG), in the back and shoulder regions during shoulder exercises with the Bodyblade Pro vs dumbbells. DESIGN: Randomized crossover study. SETTING: San Diego State University biomechanics laboratory. PARTICIPANTS: 11 healthy male subjects age 19-32 y. INTERVENTION: Subjects performed shoulder-flexion and -abduction exercises using a Bodyblade Pro and dumbbells (5, 8, and 10 lb) while EMG recorded activity of the deltoid, pectoralis major, infraspinatus, serratus anterior, and erector spinae. MAIN OUTCOME MEASURES: Average peak muscle activity (% maximum voluntary isometric contraction) was separately measured for shoulder abduction and flexion in the range of 85° to 95°. Differences among exercise devices were separately analyzed for the flexed and abducted positions using 1-way repeated-measures ANOVA. RESULTS: The Bodyblade Pro produced greater muscle activity than all the dumbbell trials. Differences were significant for all muscles measured (all P < .01) except for the erector spinae during shoulder flexion with a 10-lb dumbbell. EMG activity for the Bodyblade Pro exceeded 50% of the MVIC during both shoulder flexion and abduction. For the dumbbell conditions, only the 10-lb trials approached this effect. CONCLUSIONS: Using a Bodyblade during shoulder exercises results in greater shoulder- and back-muscle recruitment than dumbbells. The Bodyblade Pro can activate multiple muscles in a single exercise and thereby minimize the need for multiple dumbbell exercises. The Bodyblade Pro is an effective device for shoulder- and back-muscle activation that warrants further use by clinicians interested in its use for rehabilitation.

Influence of infrapatellar and suprapatellar straps on quadriceps muscle activity and onset timing during the body-weight squat.

The use of knee braces for the treatment of patellofemoral pain syndrome (PFPS) is widely documented, yet the mechanism by which such braces alleviate knee pain remains unclear. This study attempted to clarify this issue by simplifying the brace to the level of only straps. The effectiveness of an infrapatellar strap for PFPS remains controversial, and the use of a suprapatellar strap has not yet been studied. Quadriceps muscle activity and onset timing parameters were measured with surface electromyography (EMG) during a body-weight squat in 19 healthy subjects during 4 different knee-strapping conditions (infra, supra, both, and none). No differences in normalized mean or peak EMG activity in any part of the quadriceps were found. The onset timing of the vastus lateralis (VL) was significantly delayed when using an infrapatellar strap (p < 0.05) or both straps (p < 0.05) and marginally delayed when using a suprapatellar strap (p < 0.10) in comparison with the no-strap (control) condition. No differences in the vastus medialis oblique (VMO) onset timing or VMO-VL onset timing difference were found among the strapping conditions, although an improvement in timing was noted with the suprapatellar condition. The results provide novel evidence that the application of an infrapatellar strap, suprapatellar strap, or both straps improves quadriceps muscle timing imbalances by delaying VL onset. Because the largest delay in VL onset occurred when wearing both straps, the combined application of an infrapatellar and suprapatellar strap may be the most beneficial in managing patellofemoral pain. Knee straps, unlike braces, are cost effective, nonrestrictive, and can be universally fitted to any knee and based on the results deserve further study in the patellofemoral pain population.

Effect of stretch frequency and sex on the rate of gain and rate of loss in muscle flexibility during a hamstring-stretching program: a randomized single-blind longitudinal study.

This study evaluated the effects of 4 different weekly stretching protocols on the rate of gain and decline in hamstring flexibility over an 8-week period, across sex. Using a randomized single-blind design, 53 healthy subjects aged 18-46 years were assigned to 1 of 4 stretching protocols or a control group. The stretching protocols consisted of either daily or 3 times per week stretching and performed once or twice each day. These protocols differed in terms of frequency and total weekly stretching time. All the subjects stretched their hamstring muscles for 4 weeks and were measured weekly for their hip range of motion (ROM). Stretching ceased the final 4 weeks as the weekly measurements continued. The results revealed no significant differences in the rate of gain or the rate of loss between the different stretching protocols (2-way analysis of variance, F = 2.60, p > 0.05). All the stretching groups gained in hip ROM from pre to week 4 (F = 269.24, p < 0.001). After cessation, the rate of loss was similar for all the 4 stretching groups (F = 102.86, p < 0.001); all the groups retained significant gains at the end of the study (p < 0.001). The control group did not change over time. Those who stretched at least 6 times per week gained more than those who stretched 3 times per week (24 and 16.8%, respectively, F = 5.20, p < 0.05). Subject sex did not influence ROM changes (p > 0.05). Stretching appears to be equally effective, whether performed daily or 3 times per week, provided individuals stretch at least 2 times each day. Moreover, although women are more flexible than men are, there was no sex difference in terms of stretching response.

Comparing preseason frontal and sagittal plane plyometric programs on vertical jump height in high-school basketball players.

The primary purpose of this study was to evaluate whether frontal plane (FP) plyometrics, which are defined as plyometrics dominated with a lateral component, would produce similar increases in vertical jump height (VJH) compared to sagittal plane (SP) Plyometrics. Thirty-two junior varsity and varsity high-school basketball players participated in 6 weeks of plyometric training. Players participated in either FP or SP plyometrics for the entire study. Vertical jump height was measured on 3 occasions: preintervention (baseline), at week 3 of preparatory training, and at week 6 of training. Descriptive statistics were calculated for VJH. A 2-way analysis of variance (ANOVA) with repeated measures was used to test the difference in mean vertical jump scores using FP and SP training modalities. Results showed a significant effect over time for vertical jump (p < 0.001). Moreover, a significant time by protocol interaction was noted (p < 0.032). A 1-way ANOVA demonstrated that only the SP group demonstrated improvements over time, in VJH, p < 0.05. The FP group did not improve statistically. The data from this study suggest that FP plyometric training did not have a significant effect on VJH and significant improvement in VJH was seen in subjects participating in SP plyometrics thus reinforcing the specificity principle of training. However, coaches should implement both types of plyometrics because both training modalities can improve power and quickness among basketball players.

Superficial precooling on a 4-week static stretching regimen: a randomized trial.

BACKGROUND: The influence of superficial precooling on range of motion (ROM) as part of a stretching program has not been extensively studied. It is not clear if the analgesic effect can benefit a stretching program. HYPOTHESES: Superficial precooling will result in greater gains in ROM as part of a stretching program, compared with stretching without a precooling intervention. Superficial precooling will also result in greater retention in ROM gains following cessation of stretching, compared with stretching without a precooling intervention. STUDY DESIGN: Prospective randomized single-blind test-retest design. METHODS: Twenty-nine participants were randomly assigned to 1 of 2 static stretching protocols: a standard protocol (n, 14; age, 24.6 ± 5.4 years) or a precool protocol (n, 15; age, 25.1 ± 7.3 years). These samples allowed for 80% power for statistical significance testing. Both groups performed static hamstring stretching daily for 4 weeks. The precool group applied ice to the hamstring for 10 minutes before stretching. Both groups stretched for 4 weeks and then stopped stretching for the last 4 weeks. Hip ROM measures were obtained each week for 8 weeks. RESULTS: For the standard group, mean hip ROM increased from 71.4° ± 18.5° to 90.6° ± 20.5° and for the precool group, 71.5° ± 22.3° to 91.8° ± 20.9°. For the standard group, mean hip ROM decreased from 90.6° ± 20.5° to 83.9° ± 20.3° and for the precool group, 91.8° ± 20.9 to 85.0° ± 19.4°. There were no differences between groups at any time in the study (P > .05). CONCLUSIONS: Precooling had no beneficial effects on ROM or on retention of ROM. CLINICAL RELEVANCE: Cold application, before stretching, does not provide any benefit to a stretching program.

The effects of intermittent stretching following a 4-week static stretching protocol: a randomized trial.

Stretching is performed in rehabilitation and sports conditioning programs. It is not known how often during a week stretching needs to be performed to maintain flexibility. Therefore, the purpose of this study was to determine the influence of intermittent stretching (i.e., 2-3 days/week) on hip range of motion (ROM) following a 4-week, daily stretching program. This study used a randomized, single-blind, test-retest design. Healthy adult subjects, age 18 to 50 years, were randomly assigned to 1 of 2 static stretching protocols: (a) standard protocol or (b) intermittent protocol. All subjects stretched their hamstrings daily for the first 4 weeks. The standard group discontinued all stretching after 4 weeks. The intermittent group continued to stretch 2 to 3 days per week for an additional 4 weeks. All subjects were measured for hip ROM weekly for the full 8 weeks. Thirty-two subjects completed the study (standard group = 14; intermittent group = 18, mean age 24.6 years). Mean hip ROM increased (p < 0.05) for both groups from before protocol (PRE) to Week 4 (standard group gain from 71.4 +/- 18.5 degrees to 90.6 +/- 20.5 degrees and intermittent group gain from 68.6 +/- 15.7 degrees to 89.1 +/- 16.8 degrees). During the final 4 weeks, mean hip ROM decreased (p < 0.05) for the standard group from 90.6 +/- 20.5 degrees to 83.9 +/- 20.3 degrees. Mean hip ROM for the intermittent group did not decrease during the final 4 weeks of the study (89.1 +/- 16.8 degrees to 93.2 +/- 14.9 degrees, p > 0.05). Intermittent stretching (i.e., 2 or 3 days/week) is sufficient to maintain ROM gains acquired from a prior static stretching program. Clinicians and trainers may educate their clients of the benefits of intermittent stretching to maintain flexibility.

Reliability and validity of a partial weight bearing measure of lower extremity performance.

BACKGROUND: Methods of measuring lower extremity function is limited for those with partial weight bearing (PWB) status in early phases of a lower extremity rehabilitation program. OBJECTIVES: The purpose of this study was to measure intra-rater reliability of two lower extremity PWB performance measures using an incline exercise apparatus and to evaluate the concurrent validity and responsiveness to change of these two measures. METHODS: Thirty-seven adult patients with lower extremity injuries were measured on two PWB measures (PWB20 and PWB30) of lower extremity performance as well as several common measures of LE function. After initial testing, subjects were asked to return for retesting, following four to six weeks of rehabilitation intervention. Reliability of the data from the measures was tested using intraclass correlation coefficients (ICC); validity was based on bivariate correlations of the measures. The minimal detectable change (MDC) value and limb symmetry index (LSI) were used to study the responsiveness of the PWB measures. RESULTS: The ICC for the PWB20 and PWB30 were 0.95 and 0.98, respectively. The bivariate correlations of the PWB20 with stair climbing and walking speed were greater than those of the PWB30. Correlations ranged from r = 0.49 to 0.72 between the PWB measures and the functional measures. For most patients, their change in score between initial testing and follow-up exceeded the MDC; the LSI improved for all patients. CONCLUSION: Using the incline apparatus yielded reliable PWB data. In addition, performance on the PWB measures correlated fairly well with common measures of function.

Electromyographic data do not support a progressive recruitment of muscle fibers during exercise exhibiting a VO2 slow component.

The origin of the slow component (SC) of oxygen uptake kinetics, presenting during exercise above the ventilatory threshold (VT), remains unclear. Possible physiologic mechanisms include a progressive recruitment of type II muscle fibers. The purpose of this study was to examine alterations in muscle activity through electromyography (EMG) and mean power frequency (MPF) analysis during heavy cycling exercise. Eight trained cyclists (mean +/- S.E.; age = 30 +/- 3 years, height = 1771 +/- 4 cm, weight = 73.8 +/- 6.5 kg, VO2max = 4.33 +/- 0.28 l min(-1)) completed transitions from 20W to a workload equaling 50% of the difference between V(T) and VO2max. VO2 was monitored using a breath-by-breath measurement system, and EMG data were gathered from surface electrodes placed on the gastrocnemius lateralis and vastus lateralis oblique. Breath-by-breath data were time aligned, averaged, interpolated to 1-s intervals, and modeled with non-linear regression. Mean power frequency (MPF) and RMS EMG values were calculated for each minute during the exercise bout. Additionally, MPF was determined using both isolated EMG bursts and complete pedal revolutions. All subjects exhibited a VO2 SC (mean amplitude = 0.98 +/- 0.16 l min(-1)), yet no significant differences were observed during the exercise bout in MPF or RMS EMG data (p > 0.05) using either analysis technique. While it is possible that the sensitivity of EMG may be insufficient to identify changes in muscle activity theorized to affect the VO2 SC, the data indicated no relationship between MPF/EMG and the SC during heavy cycling.

Recruitment of the serratus anterior as an accessory muscle of ventilation during graded exercise.

The role of the serratus anterior (SA) as an accessory muscle of ventilation and its physiologic significance under exercising conditions remains unclear. Recent investigations have utilized the measurement of SA as an analog for respiratory muscle oxygenation. The purpose of this investigation was to examine the action of the serratus anterior via surface electromyography (EMG) and near infrared spectroscopy (NIRS) during exercise while controlling for muscular effort not related to ventilation. Nine healthy volunteers (age = 24.4 +/- 0.5 years, VO2max = 3.416 +/- 0.35 l min(-1); VEpeak = 127.5 +/- 13.1 l min(-1); TVpeak = 2.844 +/- 0.226 l) completed a graded exercise test to volitional exhaustion on a cycle ergometer. The subjects' arms were folded and relaxed at the abdomen to minimize muscular effort resulting from scapular stabilization during pushing/forward flexion of the arms associated with cycle ergometry. VO2 and V were monitored breath-by-breath throughout exercise. EMG was recorded over the right SA, and a near infrared probe was placed over the left SA. No significant differences were observed throughout the graded exercise test for tissue oxygenation (StO2) (n = 6, F[1.532, 7.661] = 0.895, P > 0.05, eta2 = 0.15) or EMG (n = 9, F[1.594, 12.75] = 3.067, P > 0.05, eta2 = 0.27). Although the recruitment of the SA has been postulated to aid in ventilation in various postures and disease states, it is concluded that it shows little muscular effort in healthy subjects during upright cycling. Additional research is needed to conclude the pertinence of utilizing StO2 of the SA as an analog for respiratory muscle oxygenation.

Development and psychometric properties of the Self-Efficacy Scale for transfers for caregivers of children requiring transfer assistance.

OBJECTIVE: To test the psychometric properties of a newly developed measure of caregiver self-efficacy, the Caregiver Self-Efficacy Scale for Transfers (CSEST), a 14-item questionnaire that measures the perceived self-efficacy of adult caregivers of dependent children and focuses on their perceived abilities and the challenges of assisting a child with restricted transfer ability. DESIGN: Reliability and validity study using survey data. SETTING: Community-based survey study. PARTICIPANTS: Adult caregivers (eg, mother, father, grandparent) of dependent minors who require transfer assistance. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Using the Rasch measurement model, the CSEST was tested for reliability and separation, validity (hierarchical and content), and factor structure. RESULTS: The CSEST yields data with sufficient reliability (reliability indices of .96 and .94 for respondents and items, respectively) as well as sufficient separation of levels of self-efficacy (item separation index, 4.13; person separation index, 5.23). The CSEST has a stable hierarchical structure with adequate content validity (standardized chi2 fit statistics <2.0) and point biserial correlations greater than .67. Factor analysis confirmed 2 insubstantial subscales; the 14-item CSEST accounted for greater than 85% of the total variance. CONCLUSIONS: The CSEST yields reliable data and valid inferences of self-efficacy from adult caregivers of children requiring transfer assistance. The CSEST may identify areas of need and/or difficulty with transfers for parents caring for dependent children.

Effect of pedaling technique on muscle activity and cycling efficiency.

The purpose of this study was to examine the acute effect of talocrural joint position on muscle activity and gross mechanical efficiency (GE). Eleven trained cyclists participated in three randomized 6-min cycling bouts at approximately 80% of maximal aerobic capacity on an electromagnetically braked cycle ergometer while oxygen consumption and muscle activity (EMG) were monitored during the subject's self-selected pedaling technique (control) and while using a dorsi- and plantarflexed pedaling technique. The mean differences in range of motion of the dorsi- and plantarflexed technique from the control position were 7.1 +/- 4.4 and 6.9 +/- 5.4 degrees , respectively. Gastrocnemius EMG activity was higher with the dorsiflexion technique than when using the self-selected control position (33.2 +/- 13.0 and 24.2 +/- 8.4 microV s, respectively; P < 0.05). Moreover, GE was 2.6% lower while riding with the dorsiflexion technique than the control position (19.0 +/- 1.2 and 19.5 +/- 1.3%, respectively; P < 0.05). The data suggested that introducing more dorsiflexion into the pedal stroke of a trained cyclist increases muscle activity of the gastrocnemius lateralis and decreased GE when compared to the self-selected pedal stroke.

Physical therapy and occupational therapy: partners in rehabilitation for persons with movement impairments.

SUMMARY The professions of physical therapy and occupational therapy have legitimate roles in the restoration of human movement in the rehabilitation process. This paper first presents a physical therapy perspective on changing trends in therapeutic exercise. Recent trends in physical therapy reflect a shift away from isolating patterns of movement and open kinetic chain exercises toward a new emphasis on functional patterns of movement and closed kinetic chain exercises. Rehabilitation of persons with hip fracture is used as an example of these shifting trends. Next, the paper presents an occupational therapy perspective. Occupational therapy's historical emphasis on the use of naturalistic occupations as the context for therapeutic exercise is described. Theoretical advantages of occupationally embedded movement are listed, and recent research in support of naturalistic occupations is summarized. Physical therapy and occupational therapy are distinct professions with autonomous outlooks and terminologies, but the responsibilities of physical therapists and occupational therapists potentially overlap in the restoration of movement. Suggestions are made for interdisciplinary teamwork whereby the holistically considered welfare of the patient is always the primary concern of all therapists.