Objective: To examine the selective influences of distinct acceleration profiles on the neuromuscular efficiency, force, and power during concentric and eccentric phases of isoinertial squatting exercise. Design: Cross-sectional study. Setting: Biomechanics laboratory of the university. Participants: A total of 38 active adults were divided according to their acceleration profiles: higher (n = 17; >2.5 m/s2) and lower acceleration group (n = 21; <2.5 m/s2). Intervention: All subjects performed squats until failure attached to an isoinertial conic pulley device monitored by surface electromyography of rectus femoris, vastus medialis, vastus lateralis, biceps femoris, and semitendinosus. Main Outcome Measures: An incremental optical encoder was used to assess maximal and mean power and force during concentric and eccentric phases. The neuromuscular efficiency was calculated using the mean force and the electromyographic linear envelope. Results: Between-group differences were observed for the maximal and mean force (Prange = .001–.005), power (P = .001), and neuromuscular efficiency (Prange = .001–.03) with higher significant values for the higher acceleration group in both concentric and eccentric phases. Conclusion: Distinct acceleration profiles affect the neuromuscular efficiency, force, and power during concentric and eccentric phases of isoinertial squatting exercise. To ensure immediate higher levels of power and force output without depriving the neuromuscular system, acceleration profiles higher than 2.5 m/s2 are preferable. The acceleration profiles could be an alternative to evolve the isoinertial exercise.
Denys Batista Campos, Isabella Christina Ferreira, Matheus Almeida Souza, Macquiden Amorim Jr, Leonardo Intelangelo, Gabriela Silveira-Nunes, and Alexandre Carvalho Barbosa
Kyung-eun Lee, Seung-min Baik, Chung-hwi Yi, Oh-yun Kwon, and Heon-seock Cynn
Context: Side bridge exercises strengthen the hip, trunk, and abdominal muscles and challenge the trunk muscles without the high lumbar compression associated with trunk extension or curls. Previous research using electromyography (EMG) reports that performance of the side bridge exercise highly activates the gluteus medius (Gmed). However, to the best of our knowledge, no previous research has investigated EMG amplitude in the hip and trunk muscles during side bridge exercise in subjects with Gmed weakness. Objective: The purpose of this study was to examine the EMG activity of the hip and trunk muscles during 3 variations of the side bridge exercise (side bridge, side bridge with knee flexion, and side bridge with knee flexion and hip abduction of the top leg) in subjects with Gmed weakness. Design: Repeated-measures experimental design. Setting: Research laboratory. Patients: Thirty subjects (15 females and 15 males) with Gmed weakness participated in this study. Intervention: Each subject performed 3 variations of the side bridge exercise in random order. Main Outcome Measures: Surface EMG was used to measure the muscle activities of the rectus abdominis, external oblique, longissimus thoracis, multifidus, Gmed, gluteus maximus, and tensor fasciae latae (TFL), and Gmed/TFL muscle activity ratio during 3 variations of the side bridge exercise. Results: There were significant differences in Gmed (F 2,56 = 110.054, P < .001), gluteus maximus (F 2,56 = 36.416, P < .001), and TFL (F 2,56 = 108.342, P < .001) muscles among the 3 side bridge exercises. There were significant differences in the Gmed/TFL muscle ratio (F 2,56 = 20.738, P < .001). Conclusion: Among 3 side bridge exercises, the side bridge with knee flexion may be effective for the individuals with Gmed weakness among 3 side bridge exercises to strengthen the gluteal muscles, considering the difficulty of the exercise and relative contribution of Gmed and TFL.
Bruno Augusto Lima Coelho, Helena Larissa das Neves Rodrigues, Gabriel Peixoto Leão Almeida, and Sílvia Maria Amado João
Context: Restriction in ankle dorsiflexion range of motion (ROM) has been previously associated with excessive dynamic knee valgus. This, in turn, has been correlated with knee pain in women with patellofemoral pain. Objectives: To investigate the immediate effect of 3 ankle mobilization techniques on dorsiflexion ROM, dynamic knee valgus, knee pain, and patient perceptions of improvement in women with patellofemoral pain and ankle dorsiflexion restriction. Design: Randomized controlled trial with 3 arms. Setting: Biomechanics laboratory. Participants: A total of 117 women with patellofemoral pain who display ankle dorsiflexion restriction were divided into 3 groups: ankle mobilization with anterior tibia glide (n = 39), ankle mobilization with posterior tibia glide (n = 39), and ankle mobilization with anterior and posterior tibia glide (n = 39). Intervention(s): The participants received a single session of ankle mobilization with movement technique. Main Outcome Measures: Dorsiflexion ROM (weight-bearing lunge test), dynamic knee valgus (frontal plane projection angle), knee pain (numeric pain rating scale), and patient perceptions of improvement (global perceived effect scale). The outcome measures were collected at the baseline, immediate postintervention (immediate reassessment), and 48 hours postintervention (48 h reassessment). Results: There were no significant differences between the 3 treatment groups regarding dorsiflexion ROM and patient perceptions of improvement. Compared with mobilization with anterior and posterior tibia glide, mobilization with anterior tibia glide promoted greater increase in dynamic knee valgus (P = .02) and greater knee pain reduction (P = .02) at immediate reassessment. Also compared with mobilization with anterior and posterior tibia glide, mobilization with posterior tibia glide promoted greater knee pain reduction (P < .01) at immediate reassessment. Conclusion: In our sample, the direction of the tibia glide in ankle mobilization accounted for significant changes only in dynamic knee valgus and knee pain in the immediate reassessment.
Arthur Alves Dos Santos, James Sorce, Alexandra Schonning, and Grant Bevill
This study evaluated the performance of 6 commercially available hard hat designs—differentiated by shell design, number of suspension points, and suspension tightening system—in regard to their ability to attenuate accelerations during vertical impacts to the head. Tests were conducted with impactor materials of steel, wood, and lead shot (resembling commonly seen materials in a construction site), weighing 1.8 and 3.6 kg and dropped from 1.83 m onto a Hybrid III head/neck assembly. All hard hats appreciably reduced head acceleration to the unprotected condition. However, neither the addition of extra suspension points nor variations in suspension tightening mechanism appreciably influenced performance. Therefore, these results indicate that additional features available in current hard hat designs do not improve protective capacity as related to head acceleration metrics.
Meaghan Hindle, Katherine Aldinger, and Geoff Dover
Context: Chronic pain is a challenge for Athletic Trainers and Athletic Therapists working in a clinical or university setting. The fear avoidance model, including catastrophizing, is well established in other health professions but is not established in Athletic Training and Athletic Therapy and may affect rehabilitation outcomes. Objective: To measure the influence of catastrophizing on rehabilitation outcomes of patients being treated in an Athletic Therapy setting. Design: Prospective single group pre–post design. Setting: Student Athletic Therapy clinic. Patients: A total of 92 patients were evaluated at initial assessment, and 49 were evaluated at follow-up. Intervention: All participants completed self-reported function questionnaires to assess level of injury and then received individualized treatments for a variety of musculoskeletal injuries. All measures were completed at initial assessment and at follow-up approximately 6 weeks later. Main Outcome Measures: The authors measured function using a variety of patient self-reported functional questionnaires: the Disability of the Arm, Shoulder, and Hand; Lower Extremity Functional Scale; the Neck Disability Index; and the Oswestry Disability Index depending on injury site. Catastrophizing was measured using the Pain Catastrophizing Scale. Results: Function significantly improved from the initial assessment to the follow-up (P > .001). Patients with acute pain experienced a significantly greater improvement in function between the initial assessment and follow-up compared with participants with chronic pain (P = .050). Those with high catastrophizing presented with lower levels of function at initial assessment (66.8%) and follow-up (72.1%) compared with those with low catastrophizing (80.8% and 87.0%, respectively). Conclusion: Similar to other studies in other professions, the function of patients with chronic pain does not improve as much compared with patients recovering from acute pain in an Athletic Therapy setting. It is important to measure patient-reported outcomes to evaluate patient rehabilitation progress. Rehabilitating patients with chronic pain is a challenge, and pain catastrophizing should be evaluated at the initial assessment since catastrophizing is associated with worse function.
Ghazala T. Saleem, Beth S. Slomine, and Stacy J. Suskauer
Context: Objective and expedient assessments of standing postural control incorporating static and dynamic tasks are necessary for identifying subtle motor deficits and clearing children to return to high-risk activities after concussion. The Revised Physical and Neurological Examination for Subtle Signs (PANESS) gaits and stations tasks evaluate both static and dynamic aspects of postural control. While the PANESS gaits and stations subscale is sensitive to concussion in youth, the benefit of each specific task for this purpose is unknown. Purpose: This study evaluated whether specific PANESS tasks identify postural impairments after youth concussion. Design: Cross-sectional study. Setting: Academicallyaffiliated research laboratory. Participants: Sixty youth, ages 10–17 years, comprised 3 groups: (1) youth symptomatic from concussion (4–14 d postinjury [n = 18]), (2) clinically-recovered youth (27–122 d postinjury [n = 15]), and (3) age- and gender-matched never-concussed controls (n = 27). Main Outcome Measure: PANESS gaits and stations tasks (6 dynamic and 3 static) at the time of the initial research visit. Results: Kruskal–Wallis statistic identified a significant main effect of group on standing on one foot (a 30-s task). Both symptomatic and clinically-recovered youth showed deficits on standing on one foot relative to controls. Conclusions: Single-leg tasks of longer duration may maximize the ability to detect residual postural deficits after concussion and can be readily incorporated in targeted sport rehabilitation protocols.
Mandeep Kaur, Daniel Cury Ribeiro, Kate E. Webster, and Gisela Sole
Context: Altered knee joint mechanics may be related to quadriceps muscle strength, time since surgery, and sex following anterior cruciate ligament reconstruction (ACLR). The aim of this study was to investigate the association between knee moments, with participant-related factors during stair navigation post-ACLR. Design: Cross-sectional study. Methods: A total of 30 participants (14 women) with ACLR, on average 7.0 (SD 4.4) years postsurgery were tested during stair ascent and descent in a gait laboratory. Motion capture was conducted using a floor-embedded force plate and 11 infrared cameras. Quadriceps concentric and eccentric muscle strength was measured with an isokinetic dynamometer at 60°/s, and peak torques recorded. Multiple regression analyses were performed between external knee flexion and adduction moments, respectively, and quadriceps peak torque, sex, and time since ACLR. Results: Higher concentric quadriceps strength and female sex accounted for 55.7% of the total variance for peak knee flexion moment during stair ascent (P < .001). None of the independent variables accounted for variance in knee adduction moment (P = .698). No significant associations were found for knee flexion and adduction moments during for stair descent. Conclusion: Higher quadriceps concentric strength and sex explains major variance in knee flexion moments during stair ascent. The strong association between muscle strength and external knee flexion moments during stair ascent indicate rehabilitation tailored for quadriceps may optimize knee mechanics, particularly for women.
Stephen P. Hebard, James E. Bissett, Emily Kroshus, Emily R. Beamon, and Aviry Reich
Sport coaches can play an influential role in athletes’ mental health help seeking through purposeful communication, destigmatization of mental health concerns, and supportive relationships. To positively engage in these behaviors, coaches require mental health knowledge (or literacy), positive attitudes about that knowledge, and self-efficacy to use that knowledge. Guided by a multidimensional health literacy framework, we conducted a content analysis of web content and scholarly literature to identify health education programming for coaches that addressed athlete mental health. A purposive sample of Olympic National Governing Bodies, collegiate athletic associations, high school sport associations, youth sport governing bodies, and the scholarly literature were analyzed. We found inconsistent programming regarding a range of mental health disorders, behaviors critical to mental health promotion, and critical components of mental health literacy. Implications and next steps for mental health literacy support for coaches are discussed.
Lindsey R. Turbyfill, Logan J. Hatley, and Alan R. Needle
Clinical Scenario: The impact of concussion in baseball athletes is far reaching although typically less studied than collision sports. The neuromotor sequelae of these injuries can have lasting effects on the high level of coordination needed in baseball skills. In professional athletes, the long-term effects of concussion combined with the high demands for performance can potentially shorten athletes’ careers. Clinical Question: Do Major League Baseball players who have had a concussion compared with those with no history of concussions have decreased batting performance after they return to full participation? Summary of Key Findings: Seven articles meeting criteria for level 2 evidence were identified in this critically appraised topic. Four of 7 studies found deficits in batting performance following concussion. However, the 3 studies that did not identify differences lacked a comparative control group. Clinical Bottom Line: Evidence supports a relationship between concussion and decreased batting performance. This suggests there is a demand for screening and rehabilitation strategies aimed at improving sport-specific neuromotor and coordination skills in these individuals. Strength of Recommendation: Collectively, the body of evidence included to answer the clinical question aligns with the strength of recommendation of B.