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 (P range = .001–.005), power (P = .001), and neuromuscular efficiency (P range = .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.
Brandon M. DeSantis, Victor R. Kalman, and Steven Browne
Antigravity treadmills are being used in rehabilitation programs but have not been used consistently with posthip labral repair arthroscopy surgeries. The purpose of this study was to review the posthip labral protocol used by eight National Collegiate Athletic Association Division I collegiate athletes (all ages 18–21) from multiple sports that used the antigravity treadmill as a bridge between “no running” and “on-ground running.” The authors found that athletes who did this returned to play between 4.5 and 7 months, had a better overall functional status, and had no re-injuries. This is the first known study of its kind available in the literature.
Ryan S. McCann, Ashley M.B. Suttmiller, Phillip A. Gribble, and Julie M. Cavallario
Athletic trainers are commonly responsible for clearing patients with ankle sprains for return to activity. What criteria athletic trainers typically use to determine return to activity readiness in this population remains unclear. The purpose of this qualitative study was to examine criteria athletic trainers use to determine patients’ return to activity readiness following an ankle sprain. Participants varied in selected clinician-, patient-rated, and functional assessments for patients with ankle sprains. As many selected methods did not agree with expert consensus recommendations, more work is likely needed to instill best practices for evaluation of patients with ankle sprains.
Ryan S. McCann, Ashley M.B. Suttmiller, Phillip A. Gribble, and Julie M. Cavallario
Athletic trainers’ reasons for selecting or avoiding certain evaluation techniques for patients with an ankle sprain are not fully understood. Such information is important to facilitating evidence-based practice and eliminating barriers. The purpose of this qualitative study was to determine what factors influence athletic trainers’ selection or avoidance of specific outcomes used to determine patients’ return to activity readiness following an ankle sprain. Participants cited many factors that facilitate and inhibit their use of best-practice recommendations and alternative methods for evaluating patients with ankle sprains. Athletic trainers’ should continue to promote facilitators and eliminate barriers to the use of best practices.
Diane Richmond, Kathleen Castro, Vaibhavi Rathod, Thais Medeiros da Costa Dias, Nelson Marinho de Lima Filho, Judith Meer, and Smita Rao
Context: Yoga is increasingly popular, not only as a form of recreational exercise but also as a physician-recommended intervention for health conditions. While serious adverse effects accompanying yoga practice are rare, poses that involve upper-extremity weight-bearing have a high risk of discomfort. To better understand factors contributing to adverse effects, there is a critical need for robust instruments that objectively evaluate pose performance. The purpose of this study was to assess the interrater reliability of an observational scale developed to assess the alignment of 3 yoga poses. Design: Cross-sectional experimental study. Methods: Thirty-eight individuals were given standardized instructions and performed 3 poses (Downward Dog, Plank, and Side Plank). Lateral videos were rated by 2 raters. A rating scale evaluating the alignment of 7 regions was developed by the study team with input from yoga teachers. Descriptive statistics were used to summarize the percentage of subjects showing ideal alignment and deviations. Interrater reliability was quantified using Cohen kappa coefficient (κ). Results: In Downward Dog, the prevalence of ideal alignment was 20%, 28%, and 37%, at the neck, shoulder, and back, respectively; κ ranged from .44 to .69. In Plank, the prevalence of ideal alignment was 31%, 45%, and 54% at the neck, shoulder, and back, respectively; κ ranged from .47 to .95. In Side Plank, the prevalence of ideal alignment was 16, 41%, and 24%, at the neck, shoulder, and back, respectively; κ ranged from .20 to .84. Conclusion: The observational scale found a high prevalence of deviations, and demonstrated fair to substantial interrater agreement.
Katherine A. Bain, Paige A. Clawson, Stacey A. Slone, Phillip A. Gribble, Johanna M. Hoch, Matthew C. Hoch, and Kyle B. Kosik
Context: Strength deficits and decreased scores on generic, dimension-specific, and region-specific health-related quality of life (HRQL) PRO measures are commonly documented among individuals with chronic ankle instability (CAI). However, it is unknown if there is a relationship between hip strength and self-reported patient-reported outcome (PRO) scores. Objective: To compare isometric peak torque for hip-extension (H-EXT) and hip-abduction (H-ABD), as well as PRO scores between CAI, lateral ankle sprain copers (LAS copers), and uninjured controls (UC). The secondary purpose was to examine the relationship between isometric hip peak torque and PROs in participants with CAI. Design: Cross-sectional. Setting: Laboratory. Participants: Sixty-three individuals, 45 women (23.02 [3.83] y, 165.91 [7.55] cm, 67.28 [11.95] kg) and 18 men (26.28 [5.43] y, 179.28 [9.01] cm, 83.87 [13.26] kg), grouped as uninjured control (n = 26), LAS coper (n = 15), or CAI (n = 22). Main Outcome Measures: The Foot and Ankle Ability Measure was used to assess region-specific HRQL. The Fear Avoidance Beliefs Questionnaire was used to assess injury-related fear. The Disablement in Physically Active was used to assess global HRQL. Isometric peak torque was measured with a handheld dynamometer for H-EXT and H-ABD. Results: No group differences were observed for H-ABD (P = .34) or H-EXT (P = .35). The CAI group had significantly worse scores on all PROs compared with LAS coper (P < .001) and HC (P < .001). Moderate–weak correlations were found between H-ABD and Foot and Ankle Ability Measure—activities of daily living (P = .047; ρ = .392) and Foot and Ankle Ability Measure-Sport (P = .013; ρ = .482) and H- EXT and Fear Avoidance Beliefs Questionnaire-Work (P = .007; ρ = −.517). Conclusions: Individuals with CAI displayed lower HRQL based on worse scores on generic, dimension-specific, and region-specific PROs compared with LAS copers and uninjured controls. There were no significant between-group differences for H-EXT and H-ABD isometric peak torque production, but there was a moderate positive relationship between isometric H-ABD and self-reported ankle disability in individuals with CAI.