Browse

You are looking at 1 - 10 of 24,787 items

Restricted access

Richard R. Suminski, Robert J. Robertson, Fredric L. Goss, Silva Arslanian, Jie Kang, Sergio DaSilva, Alan C. Utter and Kenneth F. Metz

Sixteen men completed four trials at random as follows: (Trial A) performance of a single bout of resistance exercise preceded by placebo ingestion (vitamin C); (Trial B) ingestion of 1,500 mg L-arginine and 1,500 mg L-lysine, immediately followed by exercise as in Trial A; (Trial C) ingestion of amino acids as in Trial B and no exercise; (Trial D) placebo ingestion and no exercise. Growth hormone (GH) concentrations were higher at 30,60, and 90 min during the exercise trials (A and B) compared with the resting trials (C and D) (p < .05). No differences were noted in [GH] between the exercise trials. [GH] was significantly elevated during resting conditions 60 min after amino acid ingestion compared with the placebo trial. It was concluded that ingestion of 1,500 mg arginine and 1,500 mg ly sine immediately before resistance exercise does not alter exercise-induced changes in [GH] in young men. However, when the same amino acid mixture is ingested under basal conditions, the acute secretion of GH is increased.

Restricted access

Ben D. Kern, Kim C. Graber, Amelia Mays Woods and Tom Templin

Physical education teachers have been criticized for not implementing progressive or innovative instruction resulting in enhanced student knowledge and skills for lifetime participation in physical activity. Purpose: To investigate how teachers with varying dispositions toward change perceive socializing agents and teaching context as barriers to or facilitators of making pedagogical change. Methods: Thirty-two teachers completed a survey of personal dispositions toward change and participated in in-depth interviews. Results: Teachers perceived that students’ response to instructional methods and student contact time (days/week), as well as interactions with teaching colleagues and administrators influenced their ability to make pedagogical changes. Teachers with limited student contact time reported scheduling as a barrier to change, whereas daily student contact was a facilitator. Change-disposed teachers were more likely to promote student learning and assume leadership roles. Conclusion: Reform efforts should include consideration of teacher dispositions and student contact time.

Open access

Lauren Anne Lipker, Caitlyn Rae Persinger, Bradley Steven Michalko and Christopher J. Durall

Clinical Scenario: Quadriceps atrophy and weakness are common after anterior cruciate ligament reconstruction (ACLR). Blood flow restriction (BFR) therapy, alone or in combination with exercise, has shown some promise in promoting muscular hypertrophy. This review was conducted to ascertain the extent to which current evidence supports the use of BFR for reducing quadriceps atrophy following ACLR in comparison with standard care. Clinical Question: Is BFR more effective than standard care for reducing quadriceps atrophy after ACLR? Summary of Key Findings: The literature was searched for studies that directly compared BFR treatment to standard care in patients with ACLR. Three level I randomized control trial studies retrieved from the literature search met the inclusion criteria. Clinical Bottom Line: Reviewed data suggest that a short duration (13 d) of moderate-pressure BFR combined with low-resistance muscular training does not appear to measurably affect quadriceps cross-sectional area. However, a relatively long duration (15 wk) of moderate-pressure BFR combined with low-resistance muscular training may increase quadriceps cross-sectional area to a greater extent than low-resistance muscular training alone. The results of the third randomized control trial suggest that employing BFR while immobilized in the early postoperative period may reduce quadriceps atrophy following ACLR. Additional data are needed to establish if the benefits of BFR on quadriceps atrophy after ACLR outweigh the inherent risks and costs. Strength of Recommendation: All evidence for this review was level 1 (randomized control trial) based on the Centre for Evidence-Based Medicine criteria. However, the findings were inconsistent across the 3 studies regarding the effects of BFR on quadriceps atrophy resulting in a grade “B” strength of recommendation.

Restricted access

Zakariya Nawasreh, David Logerstedt, Adam Marmon and Lynn Snyder-Mackler

Context: Manual perturbation training improves knee functional performance and mitigates abnormal gait in patients with anterior cruciate ligament (ACL) rupture. However, manual perturbation training is time- and labor-intensive for therapists. Objective: To investigate whether perturbation training administered using a mechanical device can provide effects similar to manual training on clinical measures and knee biomechanics after ACL rupture. Design: Prospective cohort (therapeutic) study. A 2 × 2 analysis of variance was used for statistical analysis. Setting: A clinical and biomechanical laboratory. Patients: Eighteen level I/II patients with acute ACL ruptures participated in this preliminary study. Intervention: Nine patients received mechanical perturbation training on an automated mechanical device (mechanical group), and 9 patients received manual perturbation training (manual group). Outcome Measures: Patients completed performance-based testing (quadriceps strength and single-legged hop tests), patient-reported questionnaires (Knee Outcome Survey-Activities of Daily Living Scale, Global Rating Score, and International Knee Documentation Committee 2000), and 3-dimensional gait analysis before (pretesting) and after (posttesting) training. Results: There was no significant group-by-time interaction found for all measures (P ≥ .18). Main effects of time were found for International Knee Documentation Committee 2000 (pretesting: 69.10 [10.95], posttesting: 75.14 [7.19]), knee excursion during weight-acceptance (pretesting: 16.01° [3.99°]; posttesting: 17.28° [3.99°]) and midstance (pretesting: 14.78° [4.13°]; posttesting: 16.92° [4.53°]) and external knee-flexion moment (pretesting: 0.43 [0.11] N m/kg/m; posttesting: 0.48 [0.11] N m/kg/m) (P ≤ .04). After accounting for pretesting groups’ differences, the mechanical group scored significantly higher on triple hops (mechanical: 96.73% [6.65%]; manual: 84.97% [6.83%]) and 6-m timed hops (mechanical: 102.07% [9.50%]; manual: 91.21 [9.42%]) (P ≤ .047) compared with manual group. Conclusion: The clinical significance of this study is the mechanical perturbation training produced effects similar to manual training, with both training methods were equally  effective at improving patients’ perception of knee function and increasing knee excursion and external flexion moment during walking after acute ACL rupture. Mechanical perturbation training is a potential treatment to improve patients’ functional and biomechanical outcomes after ACL rupture.

Restricted access

Jessica Ferreira, André Bebiano, Daniel Raro, João Martins and Anabela G. Silva

Context: Sliding and tensioning neural mobilization are used to restore normal function of the nervous system, but they impose different stresses on it. Particularly, sliding induces greater nerve excursion than tensioning. Conceivably, they might impact nervous system function differently. Objective: To compare the effects of tensioning neural mobilization versus sliding neural mobilization of the dominant lower limb on static postural control and hop testing. Design: Randomized, parallel and double blinded trial. Setting/Participants: Thirty-seven football players. Intervention(s): Participants were randomized into 2 groups: sliding neural mobilization (n = 18) or tensioning neural mobilization (n = 19) targeting the tibial nerve. Main Outcome Measures: Static postural sway was assessed with a force plate and functional performance with hop tests. Measurements were taken at baseline, after the intervention, and at 30-minute follow-up. Results: There was a significant effect of time for the center of pressure total displacement and velocity (P < .05), for the single-leg hop test (P < .05), the 6-m timed hop test (P < .05), and the cross-over hop test (P < .05), but no significant effect of the intervention. Conclusions: Sliding and tensioning neural mobilization improved postural control and hop testing in football players, and improvements remained 30 minutes after the intervention. Additional research examining the influence of neural mobilization on sensory motor impairments, postural control, and functional performance is needed.

Restricted access

Alireza Derakhshani, Amir Letafatkar and Zohre Khosrokiani

Context: Scapular downward rotation syndrome (SDRS) is an impaired alignment that causes shoulder and neck pain. Interventions may lead to the reduction of pain intensity and joint position error (JPE) and improved range of motion (ROM). Objective: To evaluate the effects of 6-week Scapular Upward Rotation and Elevation Exercises (SUREE) with and without visual feedback on pain, ROM, and JPE in people with SDRS. Study Design: Randomized control trial. Setting: Institutional practice. Participants: Forty-two young and active subjects (22.61 [1.80] y; 27 males and 15 females) with unilateral SDRS randomly assigned into 3 groups (2 intervention groups and 1 control group). Interventions: SUREE without and with visual feedback programs. Main Outcome Measures: Pain, neck-flexion and rotation ROMs, and JPE were measured using visual analog scale (score), double inclinometer method, universal goniometer method (degrees), and a dual digital inclinometer (degrees), respectively, before and after interventions. Results: The results showed statistically significant changes within the experimental groups in all variables except for the neck rotation ROM in the SUREE intervention without visual feedback (P < .05). However, there were no changes in the control group before and after the interventions in all dependent variables (P < .05). Also, there were no significant differences between both experimental groups concerning all dependent variables except for the rotation ROM (P < .05). Conclusion: The results suggest that the 6-week SUREE with and without visual feedback programs result in decreased neck pain and improved flexion ROM and JPE during active neck motions in subjects with unilateral SDRS. However, the 6-week SUREE with visual feedback may improve the neck rotation ROM in subjects with unilateral SDRS. However, further studies are needed to confirm the results of this study.

Restricted access

Michael Girdwood, Liam West, David Connell and Peter Brukner

Context: Muscle injuries of the hip stabilizers are considered rare in sport. Objective: This report presents a previously unreported case of a contact injury resulting in acute strain of quadratus femoris, obturator externus, and inferior gemellus in an amateur Australian rules football player. Design: Level 4—case report. Case Presentation: A player was tackled ipsilateral to the injured leg, while in hip flexion in a lunged position. The case describes the diagnostic process, initial management, and return to play for this athlete. Results: Following rehabilitation, the player was able to return to sport at 8 weeks without ongoing issues. Conclusions: A literature search for sports-related contact injuries to either muscle returned only one result. All other documented cases of injury to these muscle groups are confined to noncontact mechanisms or delayed presentations. Despite conventional teaching, the action of the deep external rotators of the hip appears to be positionally dependent. Knowledge of this type of injury and mechanism may be useful for future clinical reasoning and differential diagnosis in patients with this type of presentation.

Restricted access

Ali Jalalvand and Mehrdad Anbarian

Context: The link between landing parameters and lower limb muscle fatigue in association with chronic low back pain (CLBP) is not well understood. Objective: To examine the effects of fatigue on the ground reaction force components during landing in people with nonspecific CLBP. Design: Quasi-experimental study. Setting: Clinical biomechanics laboratory. Participants: A total of 44 subjects were equally divided into a healthy group and a group with CLBP. Main Outcome Measures: The ground reaction force along anterior–posterior (y) and medial–lateral (x) and vertical (z) axes, time to peak (TTP), the rate of force development, and impulses for all axes were calculated. A repeated-measures analysis of variance (group × fatigue) was used to compare the data among groups. Results: In the unfatigued conditions, the amplitudes of Fy3, Fz2, and TTP of Fy1, Fy2, Fz1, Fz2, Fz3, Fz4, rate of force development in Y in the CLBP subjects are significantly different than those in the healthy subjects (P < .05). In the fatigued conditions, the amplitudes of Fz2, Fz3, Fz4, and TTP of Fy2, Fy3, Fy4, Fz2, impulses of X 2, Z in the CLBP group were significantly different than those in the healthy subjects (P < .05). Within-group comparisons of measured Fx1, Fy1, Fy2, Fz2, Fz4 and TTP of Fx1, Fy1, Fy2, Fz2, Fz3, Fz4, impulses of X 2, z were significantly different from prefatigue to postfatigue in the healthy group (P < .05). Within-group comparisons of measured Fx1, Fy1, Fz1, Fz2 and TTP of Fx5, Fz1, impulses of X2 were significantly differed from prefatigue to postfatigue in the CLBP group (P < .05). Conclusions: It seems that TTP of ground reaction force variables in CLBP may have clinical values for rehabilitation. Muscle fatigue altered landing performance. However, patients with CLBP will respond differently to lower-extremity fatigue. These altered variables in patients with low back pain are the cause of future injuries or lower-extremity injuries that need to be addressed in further studies.

Restricted access

Ji-Hyun Lee and Tae-Lim Yoon

Context: Kinesiology tape (KT), multidirectional resistance exercise, and interventions for decreased ankle dorsiflexion range of motion are gaining popularity in the treatment of patients with chronic ankle instability (CAI). However, there is limited evidence of the effectiveness of combined interventions in patients with CAI. Objectives: To compare the effects of KT alone, KT with resistance exercise (KT + resistance), and KT with resistance and heel raise-lower exercise (KT + resistance + heel) on the results of the dynamic balance test (star excursion balance test [SEBT]), functional performance (lateral step-down test), and ankle muscle activation in patients with CAI. Design and Setting: This study used a repeated-measures design in a laboratory setting. Main Outcome Measures: The participants completed 3 different interventions with a 24-hour rest period between interventions. The SEBT, lateral step-down test, and ankle muscle activation results were used as the outcome measures. All outcomes were assessed before and immediately after the 3 interventions. Results: The results of the SEBT-anteromedial direction significantly increased with KT + resistance (78.61 [16.11] cm, P = .01, ES = 0.50) and KT + resistance + heel (76.94 [16.00] cm, P = .03, ES = 0.33) in comparison with the baseline values (73.68 [12.84] cm). Additionally, the result of the SEBT-anteromedial direction was significantly greater with KT + resistance (78.61 [16.11] cm) than with KT alone (76.00 [14.90] cm, P = .05, ES = 0.18). The number of errors during the lateral step-down test was significantly lower for the KT alone (2.16 [0.90] errors, P = .02, ES = 0.46), KT + resistance (2.10 [0.79] errors, P = .01, ES = 0.54), and KT + resistance + heel (2.03 [0.75] errors, P = .003, ES = 0.61) interventions than the baseline values (2.55 [0.85] errors). Conclusions: Patients with CAI should be encouraged to perform KT + resistance to improve balance.