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Brittney A. Luc, Adam S. Lepley, Michael A. Tevald, Phillip A. Gribble, Donald B. White and Brian G. Pietrosimone

Context:

Alterations in corticomotor excitability are observed in a variety of patient populations, including the musculature surrounding the knee and ankle after joint injury. Active motor threshold (AMT) and motor-evoked-potential (MEP) amplitudes elicited through transcranial magnetic stimulation (TMS) are outcome measures used to assess corticomotor excitability and have been deemed reliable in upper-extremity musculature. However, there are few studies assessing the reliability of TMS measures in lower-extremity musculature.

Objective:

To determine the intersession reliability of AMT and MEP amplitudes over 14 and 28 d in the quadriceps and fibularis longus (FL).

Design:

Descriptive laboratory study.

Setting:

University laboratory

Participants:

20 able-bodied volunteers (10 men, 10 women; 22.35 ± 2.3 y, 1.71 ± 0.11 m, 73.61 ± 16.77 kg).

Main Outcome Measures:

AMT and MEP amplitudes were evaluated at 95%, 100%, 105%, 110%, 120%, 130%, and 140% of AMT in the dominant and nondominant quadriceps and FL. Interclass correlation coefficients (ICCs) were used to assess reliability for absolute agreement and internal consistency between baseline and 2 follow-up sessions at 14 and 28 d postbaseline. Each ICC was fit with the best-fit straight line or parabola to smooth out noise in the observations and best determine if a pattern existed in determining the most reliable MEP value.

Results:

All muscles yielded strong ICCs between baseline and both time points for AMT. MEPs in both the quadriceps and FL produced varying degrees of reliability, with the greatest reliability demonstrated on day 28 at 130% and 140% of AMT in the quadriceps and FL, respectively. The dominant FL muscle showed a significant pattern; as TMS intensity increased, MEP reliability increased.

Conclusion:

TMS can be used to reliably identify corticomotor alterations after therapeutic interventions, as well as monitor disease progression.

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Allyson M. Carter, Stephen J. Kinzey, Linda F. Chitwood and Judith L Cole

Context:

Proprioceptive neuromuscular facilitation (PNF) is commonly used before competition to increase range of motion. It is not known how it changes muscle response to rapid length changes.

Objective:

To determine whether PNF alters hamstring muscle activity during response to rapid elongation.

Design:

2 X 2 factorial.

Setting:

Laboratory.

Participants:

Twenty-four women; means: 167.27 cm, 58.92 kg, 21.42 y, 18.41% body fat, 21.06 kg/m2 BMI.

intervention:

Measurements before and after either rest or PNF were compared.

Main Outcome Measures:

Average muscle activity immediately after a rapid and unexpected stretch, 3 times pretreatment and posttreatment, averaged into 2 pre-and post- measures.

Results:

PNF caused decreased activity in the biceps femoris during response to a sudden stretch (P = .04). No differences were found in semitendinosus activity (P = .35).

Conclusions:

Decreased muscle activity likely results from acute desensitization of the muscle spindle, which might increase risk of muscle and tendon injury.

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Lindsey K. Lepley, Abbey C. Thomas, Scott G. McLean and Riann M. Palmieri-Smith

Context:

As individuals returning to activity after anterior cruciate ligament reconstruction (ACLr) likely experience fatigue, understanding how fatigue affects knee-muscle activation patterns during sport-like maneuvers is of clinical importance. Fatigue has been suggested to impair neuromuscular control strategies. As a result, fatigue may place ACLr patients at increased risk of developing posttraumatic osteoarthritis (OA).

Objective:

To determine the effects of fatigue on knee-muscle activity post-ACLr.

Design:

Case control.

Setting:

University laboratory.

Participants:

12 individuals 7–10 mo post-ACLr (7 male, 5 female; age 22.1 ± 4.7 y; 1.8 ± 0.1 m; mass 77.7 ± 11.9 kg) and 13 controls (4 male, 9 female; age 22.9 ± 4.3 y; 1.7 ± 0.1 m; mass 66.9 ± 9.8 kg).

Interventions:

Fatigue was induced via repetitive sets of double-leg squats (n = 8), which were interspersed with sets of single-leg landings (n = 3), until squats were no longer possible.

Main Outcome Measures:

2 × 2 repeated-measures ANOVA was used to detect the main effects of group (ACLr, control) and fatigue state (prefatigue, postfatigue) on quadriceps:hamstring cocontraction index (Q:H CCI).

Results:

All subjects demonstrated higher Q:H CCI at prefatigue compared with postfatigue (F 1,23 = 66.949, P ≤ .001). Q:H CCI did not differ between groups (F 1,23 = 0.599, P = .447).

Conclusions:

The results indicate that regardless of fatigue state, ACLr individuals are capable of restoring muscle-activation patterns similar to those in healthy subjects. As a result, excessive muscle cocontraction, which has been hypothesized as a potential mechanism of posttraumatic OA, may not contribute to joint degeneration after ACLr.

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Yoshifumi Kijima, Ryoji Kiyama, Masaki Sekine, Toshiyo Tamura, Toshiro Fujimoto, Tetsuo Maeda and Tadasu Ohshige

bilateral thigh could estimate whether a stroke patient could walk independently or not. We consider that accelerometers could estimate gait quality relating to gait independence more objectively and in greater detail than simple visual observation. Such additional information would be extremely beneficial

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Tomohiro Yasuda

the American College of Sports Medicine Guidelines for Use of Human Subjects were adopted in this study. The study was approved by the ethics committee of the School of Nursing in Seirei Christopher University. Abe et al 22 revealed that muscle thickness (MT) at the anterior thigh is strongly

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Jan Wilke, Philipp Niemeyer, Daniel Niederer, Robert Schleip and Winfried Banzer

(rolled strokes per minute, Figure  1 ), which has not been investigated before, might represent a more decisive effect modifier. Figure 1 —Foam rolling velocity can be determined by the number of completed strokes per minute. Regarding the anterior thigh, 1 stroke consists of rolling either back or forth

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Amandda de Souza, Cristiano Gomes Sanchotene, Cristiano Moreira da Silva Lopes, Jader Alfredo Beck, Affonso Celso Kulevicz da Silva, Suzana Matheus Pereira and Caroline Ruschel

gains in knee and hip ROM in soccer players immediately after SMR of the anterior and posterior thigh muscles. Mohr et al 19 also verified increased hip-flexion ROM in physically active individuals after SMR of the posterior thigh muscles (3 × 60 s). However, other studies did not find improvements

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Bronwyn K. Clark, Nyssa T. Hadgraft, Takemi Sugiyama and Elisabeth A. Winkler

) was always measured via the activPAL. Two wear positions that researchers using accelerometers often employ to collect movement and posture data (thigh, wrist) were evaluated, with three beacon configurations (wall, desk or both). This enabled evaluation across a range of feasible options (single

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Thomas Haugen, Jørgen Danielsen, Leif Olav Alnes, David McGhie, Øyvind Sandbakk and Gertjan Ettema

specific variables related to front- and back-side mechanics are associated with sprint performance. Figure 1 —Definition of angles. The black dot represents CoM. CoM indicates center of mass; θ trunk , trunk angle relative to horizontal; θ thigh , thigh angle relative to horizontal, where an angle of 0

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Amber Watts, Mauricio Garnier-Villarreal and Paul Gardiner

( Rosenberger et al., 2013 ). Thigh or waist placement of postural monitors have higher rates of accuracy compared to wrist worn monitors ( Janssen & Cliff, 2015 ; Yang & Hsu, 2009 ). The activPAL ™ postural monitor, worn on the thigh, uses both postural angle and acceleration to measure sitting. It can