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Marissa C. Gradoz, Lauren E. Bauer, Terry L. Grindstaff and Jennifer J. Bagwell

pathologies. 5 However, hip rotation ROM can be tested in supine with the hip flexed to 90°, 3 seated with the hip flexed to 90°, 6 or prone with the hip extended to neutral. 4 , 7 There is no standardized position for measuring hip rotation. Knowledge regarding the reliability of different hip rotation

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Danielle Nesbitt, Sergio Molina, Ryan Sacko, Leah E. Robinson, Ali Brian and David Stodden

MC measures used in children and adolescents, common measures of “functional capacity,” as assessed in aging populations, can be viewed as measures of MC (i.e., walking speed, supine-to-stand, timed up and go, etc.) ( Corsonello et al., 2012 ; Rikli & Jones, 2001 ; Volpato et al., 2011 ). In

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Barry P. Pereira, Ashvin Thambyah and Taeyong Lee

This study investigates the altered thoracohumeral kinematics when forearm rotation is restricted while performing five activities requiring pronation and supination. Two splints simulated both a fixed-supinated or fixed-neutral forearm in six healthy subjects; the three-dimensional coupled relationship among motion about the forearm, elbow, and shoulder were analyzed. In using a screwdriver, the normal range of forearm rotation of 77.6° (SD = 30.8°) was reduced in the fixed-supinated to 11.3° (SD = 2.9°) and fixed-neutral to 18.2° (SD = 6.2°). This restriction from the fixed-supinated and fixed-neutral forearms was compensated at the shoulder by a significant increase in the total range of (1) ad/abduction by 57.3° and 62.8° respectively (p < .001), (2) forward-reverse flexion (24.3° and 18.2° respectively; p < .05) and (3) internal-external rotation (37.1° and 44.2° respectively; p < .001). A similar result was demonstrated for the doorknob activity. The elbow did not significantly contribute to forearm rotation (p = .14), and is believed to be due to the elbow axis being orthogonal and oblique to the forearm axis. For open kinetic-chain activities, with a fixed-supinated forearm performing there was a significant coupled increase in ad/abduction (p < .05) and int/external rotation (p < .05) for the phone and feeding tasks, with the phone task also having a significantly increased forward shoulder flexion (p < .05). For the fixed-neutral forearm, significant compensatory movement was only seen in the feeding task with increased ad/abduction and internal-external shoulder rotation (p < .05) and the card inserting task with increased ad/abduction and forward-reverse shoulder flexion. Limited forearm function requires compensatory motion from adjacent joints to perform activities that require pronation and supination. This study quantifies the compensatory mechanism about the shoulder in a forearm limited in prosupination.

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Marie A. Johanson, Megan Armstrong, Chris Hopkins, Meghan L. Keen, Michael Robinson and Scott Stephenson

Context:

Stretching exercises are commonly prescribed for patients and healthy individuals with limited extensibility of the gastrocnemius muscle.

Objective:

To determine if individuals demonstrate more dorsiflexion at the ankle/rear foot and less at the midfoot after a gastrocnemius-stretching program with the subtalar joint (STJ) positioned in supination compared with pronation.

Design:

Randomized controlled trial.

Setting:

Biomechanical laboratory.

Participants:

22 volunteers with current or recent history of lower-extremity cumulative trauma and gastrocnemius tightness (10 women and 4 men, mean age 28 y) randomly assigned to stretching groups with the STJ positioned in either pronation (n = 11) or supination (n = 11).

Intervention:

3-wk home gastrocnemius-stretching program using a template to place the subtalar joint in either a pronated or a supinated position.

Main Outcome Measures:

A 7-camera Vicon motion-analysis system measured ankle/rear-foot dorsiflexion and midfoot dorsiflexion of all participants during stretching with the STJ positioned in both pronation and supination before and after the 3-wk gastrocnemius-stretching program.

Results:

A 2-way mixed-model ANOVA revealed a significant interaction (P = .019). At posttest, the group who performed the 3-week stretching program with the STJ positioned in pronation demonstrated more increased ankle/rear-foot dorsiflexion when measured with the STJ in pronation than the group who performed the 3-wk stretching program with the STJ positioned in supination. No significant main effect of stretching group or interaction for dorsiflexion at the midfoot was detected (P = .755 and P = .820, respectively).

Conclusion:

After a 3-wk gastrocnemius-stretching program, when measuring dorsiflexion with the STJ positioned in supination, the participants who completed a 3-wk gastrocnemius stretching program with the STJ positioned in pronation showed more increased dorsiflexion at the ankle/rear foot than participants who completed the stretching program with the STJ positioned in supination.

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David Herzig, Moreno Testorelli, Daniela Schäfer Olstad, Daniel Erlacher, Peter Achermann, Prisca Eser and Matthias Wilhelm

Background:

It is increasingly popular to use heart-rate variability (HRV) to tailor training for athletes. A time-efficient method is HRV assessment during deep sleep.

Aim:

To validate the selection of deep-sleep segments identified by RR intervals with simultaneous electroencephalography (EEG) recordings and to compare HRV parameters of these segments with those of standard morning supine measurements.

Methods:

In 11 world-class alpine skiers, RR intervals were monitored during 10 nights, and simultaneous EEGs were recorded during 2–4 nights. Deep sleep was determined from the HRV signal and verified by delta power from the EEG recordings. Four further segments were chosen for HRV determination, namely, a 4-h segment from midnight to 4 AM and three 5-min segments: 1 just before awakening, 1 after waking in supine position, and 1 in standing after orthostatic challenge. Training load was recorded every day.

Results:

A total of 80 night and 68 morning measurements of 9 athletes were analyzed. Good correspondence between the phases selected by RR intervals vs those selected by EEG was found. Concerning root-mean-squared difference of successive RR intervals (RMSSD), a marker for parasympathetic activity, the best relationship with the morning supine measurement was found in deep sleep.

Conclusion:

HRV is a simple tool for approximating deep-sleep phases, and HRV measurement during deep sleep could provide a time-efficient alternative to HRV in supine position.

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Danielle Nesbitt, Sergio L. Molina, Maria Teresa Cattuzzo, Leah E. Robinson, David Phillips and David Stodden

This paper examined relationships between qualitative (developmental sequences) and quantitative (time) performance in rising from a supine position in early childhood. One hundred twenty two children ranging in age from 3 to 5 years were videotaped for five trials of rising from a supine position. Children’s performance on the supine-to-stand (STS) task was quite variable in terms of both qualitative movement patterns and time (mean = 2.37 s, SD = .60). Results: Component sequences were moderately to strongly correlated with each other (r = .387 to .791). Upper-extremity (r = –.383) and axial (r = –.416) component levels also were inversely correlated with STS time. Results indicated a strong coordinative link between the development of trunk control (i.e., axial movement) and upper-extremity movement levels (r = .791), and together they demonstrated the strongest impact on the ability to rise quickly. These data provide important information relating to a child’s motor development that may have clinical relevance for diagnosis. It provides also a greater understanding on how to improve performance on this task. Future research should examine qualitative and quantitative aspects of STS performance to understand its predictive utility as a lifespan assessment of motor competence and its potential importance as a measure to predict healthrelated variables and functional capability across the lifespan.

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Benno M. Nigg and H. Alexander Bahlsen

The purpose of this study was to determine the influence of lateral heel flare on pronation, external impact forces, and takeoff supination for different midsole constructions. Data were collected using force platforms and high-speed film cameras. Fourteen male subjects participated in the study, running heel-toe at a speed of 4 m/s. The analysis of kinetic and kinematic variables showed that changes in lateral heel flare of 16°, 0°, and a rounded heel can be used to influence initial pronation during heel-toe running. It could be shown that changes in lateral heel flare do not have a relevant influence on changes in total and/or maximal pronation. Changes in lateral heel flare do have an effect on vertical impact force peaks if the midsole is relatively hard but not if the midsole is relatively soft. Based on the present study, a running shoe with a relatively hard midsole material and a neutral flare would have low initial pronation values and low vertical impact force peaks.

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John H. Hollman, Tyler A. Berling, Ellen O. Crum, Kelsie M. Miller, Brent T. Simmons and James W. Youdas

performed without specific cueing strategies, hamstring recruitment preceded gluteus maximus recruitment; however, verbal cueing to extend the hip with gluteal muscles resulted in near simultaneous gluteus maximus and hamstring recruitment and stronger gluteal activation. 11 The supine bridging exercise is

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Júlio A. Costa, João Brito, Fábio Y. Nakamura, Eduardo M. Oliveira and António N. Rebelo

Purpose: To assess the sensitivity of nocturnal heart-rate-variability-monitoring methods to the effects of late-night soccer training sessions in female athletes. Methods: Eleven female soccer players competing in the first division of the Portuguese soccer league wore heart-rate monitors during sleep at night throughout a 1-wk competitive in-season microcycle, after late-night training sessions (n = 3) and rest days (n = 3). Heart rate variability was analyzed through “slow-wave sleep episode” (10-min duration) and “hour by hour” (all the RR intervals recorded throughout the hours of sleep). Training load was quantified by session rating of perceived exertion (281.8 [117.9] to 369.0 [111.7] arbitrary units [a.u.]) and training impulse (77.5 [36.5] to 110.8 [31.6] a.u.), added to subjective well-being ratings (Hopper index = 11.6 [4.4] to 12.8 [3.2] a.u.). These variables were compared between training and rest days using repeated-measures analysis of variance. Results: The log-transformed slow-wave sleep-episode cardiac autonomic activity (lnRMSSD [natural logarithm of the square root of the mean of the sum of the squares of differences between adjacent normal RR intervals] varying between 3.92 [0.57] and 4.20 [0.60] ms; ηp2=.16; 95% confidence interval, .01–.26), lnHF (natural logarithm of high frequency), lnLF (natural logarithm of low frequency), lnSD1 (natural logarithm of short-term beat-to-beat variability), and lnSD2 (natural logarithm of long-term beat-to-beat variability), and the nontransformed LF/HF were not different among night-training session days and rest days (P > .05). Considering the hour-by-hour method (lnRMSSD varying between 4.05 [0.35] and 4.33 [0.32] ms; ηp2=.46; 95% confidence interval, .26–.52), lnHF, lnLF, lnSD1, and lnSD2 and the nontransformed LF/HF were not different among night-training session days and rest days (P > .05). Conclusion: Late-night soccer training does not seem to affect nocturnal slow-wave sleep-episode and hour-by-hour heart-rate-variability indices in highly trained athletes.

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Hannah Horris, Barton E. Anderson, R. Curtis Bay and Kellie C. Huxel Bliven

contraction. 6 As body positions change and postural demands increase, such as when moving from supine to seated to standing positions, the diaphragm’s ability to maintain both respiration and postural stabilization roles may be challenged, thus increasing the propensity for altered breathing mechanics in