Matching Items (15)

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The Role of Descending Modulation in Manual Therapy and Its Analgesic Implications: A Narrative Review

Description

Manual therapy has long been a component of physical rehabilitation programs, especially to treat those in pain. The mechanisms of manual therapy, however, are not fully understood, and it has

Manual therapy has long been a component of physical rehabilitation programs, especially to treat those in pain. The mechanisms of manual therapy, however, are not fully understood, and it has been suggested that its pain modulatory effects are of neurophysiological origin and may be mediated by the descending modulatory circuit. Therefore, the purpose of this review is to examine the neurophysiological response to different types of manual therapy, in order to better understand the neurophysiological mechanisms behind each therapy’s analgesic effects. It is concluded that different forms of manual therapy elicit analgesic effects via different mechanisms, and nearly all therapies appear to be at least partially mediated by descending modulation. Additionally, future avenues of mechanistic research pertaining to manual therapy are discussed.

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Date Created
  • 2015-11-29

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Acute effects of anterior thigh foam rolling on hip angle, knee angle, and rectus femoris length in the modified Thomas test

Description

Background. Foam rolling has been shown to acutely increase range of motion (ROM) during knee flexion and hip flexion with the experimenter applying an external force, yet no study to

Background. Foam rolling has been shown to acutely increase range of motion (ROM) during knee flexion and hip flexion with the experimenter applying an external force, yet no study to date has measured hip extensibility as a result of foam rolling with controlled knee flexion and hip extension moments. The purpose of this study was to investigate the acute effects of foam rolling on hip extension, knee flexion, and rectus femoris length during the modified Thomas test.
Methods. Twenty-three healthy participants (male = 7; female = 16; age = 22 ± 3.3 years; height = 170 ± 9.18 cm; mass = 67.7 ± 14.9 kg) performed two, one-minute bouts of foam rolling applied to the anterior thigh. Hip extension and knee flexion were measured via motion capture before and after the foam rolling intervention, from which rectus femoris length was calculated.
Results. Although the increase in hip extension (change = +1.86° (+0.11, +3.61); z(22) = 2.08; p = 0.0372; Pearson’s r = 0.43 (0.02, 0.72)) was not due to chance alone, it cannot be said that the observed changes in knee flexion (change = −1.39° (−5.53, +2.75); t(22) = −0.70; p = 0.4933; Cohen’s d = − 0.15 (−0.58, 0.29)) or rectus femoris length (change = −0.005 (−0.013, +0.003); t(22) = −1.30; p = 0.2070; Cohen’s d = − 0.27 (−0.70, 0.16)) were not due to chance alone.
Conclusions. Although a small change in hip extension was observed, no changes in knee flexion or rectus femoris length were observed. From these data, it appears unlikely that foam rolling applied to the anterior thigh will improve passive hip extension and knee flexion ROM, especially if performed in combination with a dynamic stretching protocol.

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Date Created
  • 2015-09-24

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The modified Thomas test is not a valid measure of hip extension unless pelvic tilt is controlled

Description

The modified Thomas test was developed to assess the presence of hip flexion contracture and to measure hip extensibility. Despite its widespread use, to the authors’ knowledge, its criterion reference

The modified Thomas test was developed to assess the presence of hip flexion contracture and to measure hip extensibility. Despite its widespread use, to the authors’ knowledge, its criterion reference validity has not yet been investigated. The purpose of this study was to assess the criterion reference validity of the modified Thomas test for measuring peak hip extension angle and hip extension deficits, as defined by the hip not being able to extend to 0º, or neutral. Twenty-nine healthy college students (age = 22.00 ± 3.80 years; height = 1.71 ± 0.09 m; body mass = 70.00 ± 15.60 kg) were recruited for this study. Bland–Altman plots revealed poor validity for the modified Thomas test’s ability to measure hip extension, which could not be explained by differences in hip flexion ability alone. The modified Thomas test displayed a sensitivity of 31.82% (95% CI [13.86–54.87]) and a specificity of 57.14% (95% CI [18.41–90.10]) for testing hip extension deficits. It appears, however, that by controlling pelvic tilt, much of this variance can be accounted for (r = 0.98). When pelvic tilt is not controlled, the modified Thomas test displays poor criterion reference validity and, as per previous studies, poor reliability. However, when pelvic tilt is controlled, the modified Thomas test appears to be a valid test for evaluating peak hip extension angle.

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Created

Date Created
  • 2016-08-11

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Effects of load on good morning kinematics and EMG activity

Description

Many strength and conditioning coaches utilize the good morning (GM) to strengthen the hamstrings and spinal erectors. However, little research exists on its electromyography (EMG) activity and kinematics, and how

Many strength and conditioning coaches utilize the good morning (GM) to strengthen the hamstrings and spinal erectors. However, little research exists on its electromyography (EMG) activity and kinematics, and how these variables change as a function of load. The purpose of this investigation was to examine how estimated hamstring length, integrated EMG (IEMG) activity of the hamstrings and spinal erectors, and kinematics of the lumbar spine, hip, knee, and ankle are affected by changes in load. Fifteen trained male participants (age = 24.6 ± 5.3 years; body mass = 84.7 ± 11.3 kg; height = 180.9 ± 6.8 cm) were recruited for this study. Participants performed five sets of the GM, utilizing 50, 60, 70, 80, and 90% of one-repetition maximum (1RM) in a randomized fashion. IEMG activity of hamstrings and spinal erectors tended to increase with load. Knee flexion increased with load on all trials. Estimated hamstring length decreased with load. However, lumbar flexion, hip flexion, and plantar flexion experienced no remarkable changes between trials. These data provide insight as to how changing the load of the GM affects EMG activity, kinematic variables, and estimated hamstring length. Implications for hamstring injury prevention are discussed. More research is needed for further insight as to how load affects EMG activity and kinematics of other exercises.

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Created

Date Created
  • 2015-01-06

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Differences in unilateral chest press muscle activation and kinematics on a stable versus unstable surface while holding one versus two dumbbells

Description

Training the bench press exercise on a traditional flat bench does not induce a level of instability as seen in sport movements and activities of daily living. Twenty participants were

Training the bench press exercise on a traditional flat bench does not induce a level of instability as seen in sport movements and activities of daily living. Twenty participants were recruited to test two forms of instability: using one dumbbell rather than two and lifting on the COR bench compared to a flat bench. Electromyography (EMG) amplitudes of the pectoralis major, middle trapezius, external oblique, and internal oblique were recorded and compared. Differences in range of motion (ROM) were evaluated by measuring an angular representation of the shoulder complex. Four separate conditions of unilateral bench press were tested while lifting on a: flat bench with one dumbbell, flat bench with two dumbbells, COR Bench with one dumbbell, and COR Bench with two dumbbells. The results imply that there are no differences in EMG amplitude or ROM between the COR bench and traditional bench. However, greater ROM was found to be utilized in the single dumbbell condition, both in the COR bench and the flat bench.

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Created

Date Created
  • 2015-10-27

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A comparison of two gluteus maximus EMG maximum voluntary isometric contraction positions

Description

Background. The purpose of this study was to compare the peak electromyography (EMG) of the most commonly-used position in the literature, the prone bent-leg (90°) hip extension against manual resistance

Background. The purpose of this study was to compare the peak electromyography (EMG) of the most commonly-used position in the literature, the prone bent-leg (90°) hip extension against manual resistance applied to the distal thigh (PRONE), to a novel position, the standing glute squeeze (SQUEEZE).
Methods. Surface EMG electrodes were placed on the upper and lower gluteus maximus of thirteen recreationally active females (age = 28.9 years; height = 164 cm; body mass = 58.2 kg), before three maximum voluntary isometric contraction (MVIC) trials for each position were obtained in a randomized, counterbalanced fashion.
Results. No statistically significant (p < 0.05) differences were observed between PRONE (upper: 91.94%; lower: 94.52%) and SQUEEZE (upper: 92.04%; lower: 85.12%) for both the upper and lower gluteus maximus. Neither the PRONE nor SQUEEZE was more effective between all subjects.
Conclusions. In agreement with other studies, no single testing position is ideal for every participant. Therefore, it is recommended that investigators employ multiple MVIC positions, when possible, to ensure accuracy. Future research should investigate a variety of gluteus maximus MVIC positions in heterogeneous samples.

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Date Created
  • 2015-09-22

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Biomechanical implications of skeletal muscle hypertrophy and atrophy: a musculoskeletal model

Description

Muscle hypertrophy and atrophy occur frequently as a result of mechanical loading or unloading, with implications for clinical, general, and athletic populations. The effects of muscle hypertrophy and atrophy on

Muscle hypertrophy and atrophy occur frequently as a result of mechanical loading or unloading, with implications for clinical, general, and athletic populations. The effects of muscle hypertrophy and atrophy on force production and joint moments have been previously described. However, there is a paucity of research showing how hypertrophy and atrophy may affect moment arm (MA) lengths. The purpose of this model was to describe the mathematical relationship between the anatomical cross-sectional area (ACSA) of a muscle and its MA length. In the model, the ACSAs of the biceps brachii and brachialis were altered to hypertrophy up to twice their original size and to atrophy to one-half of their original size. The change in MA length was found to be proportional to the arcsine of the square root of the change in ACSA. This change in MA length may be a small but important contributor to strength, especially in sports that require large joint moments at slow joint angular velocities, such as powerlifting. The paradoxical implications of the increase in MA are discussed, as physiological factors influencing muscle contraction velocity appear to favor a smaller MA length for high velocity movements but a larger muscle MA length for low velocity, high force movements.

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Created

Date Created
  • 2015-11-30

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The Effects of Forearm Wearable Resistance on Horizontal Force-Velocity Profiles in Sprinting

Description

Given the importance of arm mechanics in sprinting and the utility of F-V profiles, the purpose of the following study was to determine the effects of forearm WR on the

Given the importance of arm mechanics in sprinting and the utility of F-V profiles, the purpose of the following study was to determine the effects of forearm WR on the horizontal F-V profile during sprinting. To determine the effect of forearm WR on the horizontal F-V profile during sprinting, a cross-sectional, repeated measure within subjects design was used, with athletes assessed both with and without forearm WR. The WR condition used 2% BM attached to the forearms. In a randomized order, subjects performed a series of maximal effort 30 m sprints; two unloaded sprints and four with WR. Three sprints were executed from a block start: one unloaded, and two with WR. The additional three sprints were executed from a split-stance start: one unloaded and two with WR. From this study, 2%BM WR was found to significantly increase sprint times from both block and standing starts. It also significantly decreased V0 and Fsystem from a block start and Psystem from a standing start. The significance from a block start may imply the arm’s greater role during the start and acceleration phases of sprinting during that position. The overloading of V0 from a block start in the F-V profile points to forearm WR as a possible tool for athletes to use during training who are overly force dominant from a block start and need to shift their profile to V0 dominance or balance in general.

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Date Created
  • 2019-05

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Injury Prevention of Young Adult Competitive Athletes

Description

Injury Prevention of Young Adult Competitive Athletes Abstract: This literature review covers many aspects of health and injury prevention that affects the young adult population. This review will begin to

Injury Prevention of Young Adult Competitive Athletes Abstract: This literature review covers many aspects of health and injury prevention that affects the young adult population. This review will begin to formulate a general guideline for sustaining performance while minimizing the incidence for injury. This population is specifically narrowed down to competitive athletes between the ages of 16-22. Some of the topics covered in this paper are the effects of macro-nutrients and micro-nutrients such as iron, calcium, vitamin D and vitamin C, on the body. Along with relating nutrition to lowering the risk of injury, there are also other topics covered such as sleep, stress relief in the form of binaural sounds, training and over-training. Nutrition topics include carbohydrates, proteins and fats, which are then split into their respective roles inside the body. These macro-nutrients are also associated with recovery and the timing and quantity consumed can be at optimal levels for competitive athletes based on gender, age and size. The vitamins and minerals discussed are also important factors in injury prevention related to bone, ligament and muscle strength. These micro-nutrients are also related to hormone regulation and immune system response which are necessary in mitigating the risk of injury in the population being analyzed. Finally, there is a training section of this literary review which covers monitoring external and internal loads experienced by the athletes, movement patterns as well as flexibility, and how to respond to over-training syndrome and overreaching in young adult athletes. Creating a balance between all aspects covered will result in a high likelihood of reducing the risk for injury in the young adult population.

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Date Created
  • 2016-12

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Keys to the Mind of an Elite Pole Vaulter: An Investigation of Psychological Skills and Mental Toughness

Description

Athletes at any level of competition face high-stress environments in which they are still expected to perform at a high level. Because of this, athletes require mental toughness in order

Athletes at any level of competition face high-stress environments in which they are still expected to perform at a high level. Because of this, athletes require mental toughness in order to skillfully perform and hopefully outperform their opponents. Mental toughness in sport is a term used to describe a variety of psychological skills that an athlete utilizes that allows them to perform better and more consistently than their competitors. This study was designed to determine whether mental toughness distinguished pole vaulters at three different levels of competition. It was hypothesized that post-collegiate athletes would have higher mental toughness scores than collegiate athletes who would subsequently score higher than high school athletes. Two questionnaires were given to high school, collegiate, and post-collegiate pole vaulters (n = 65) to determine total mental toughness scores as well as scores for eight different subcategories of mental toughness including motivation, self-belief, intensity, focus, control, coping, thriving on pressure, and assertiveness. ANOVA and multiple comparisons demonstrated that mental toughness differentiated post-collegiate pole vaulters from high school pole vaulters, but not between collegiate and post-collegiate. Additionally, collegiate and post-collegiate vaulters scored significantly higher than high school vaulters in the subcategories of motivation and control. Data also showed that male competitors demonstrated significantly higher mental toughness scores than female athletes on both questionnaires. Based on the research, knowing that mental toughness scores differentiate high school pole vaulters from elite pole vaulters (particularly in the areas of control and motivation) could set the foundation for training programs and targeted psychological interventions for younger athletes.

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Date Created
  • 2016-12