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Study Design: Controlled laboratory study using a repeated-measures, counterbalanced design., Objectives: To test the ability of 8 Swiss ball exercises (roll-out, pike, knee-up, skier, hip extension right, hip extension left, decline push-up, and sitting march right) and 2 traditional abdominal exercises (crunch and bent-knee sit-up) on activating core (lumbopelvic hip complex) musculature., Background: Numerous Swiss ball abdominal exercises are employed for core muscle strengthening during training and rehabilitation, but there are minimal data to substantiate the ability of these exercises to recruit core muscles. It is also unknown how core muscle recruitment in many of these Swiss ball exercises compares to core muscle recruitment in traditional abdominal exercises such as the crunch and bent-knee sit-up., Methods: A convenience sample of 18 subjects performed 5 repetitions for each exercise. Electromyographic (EMG) data were recorded on the right side for upper and lower rectus abdominis, external and internal oblique, latissimus dorsi, lumbar paraspinals, and rectus femoris, and then normalized using maximum voluntary isometric contractions (MVICs)., Results: EMG signals during the roll-out and pike exercises for the upper rectus abdominis (63% and 46% MVIC, respectively), lower rectus abdominis (53% and 55% MVIC, respectively), external oblique (46% and 84% MVIC, respectively), and internal oblique (46% and 56% MVIC, respectively) were significantly greater compared to most other exercises, where EMG signals ranged between 7% to 53% MVIC for the upper rectus abdominis, 7% to 44% MVIC for the lower rectus abdominis, 14% to 73% MVIC for the external oblique, and 16% to 47% MVIC for the internal oblique. The lowest EMG signals were consistently found in the sitting march right exercise. Latissimus dorsi EMG signals were greatest in the pike, knee-up, skier, hip extension right and left, and decline push-up (17%-25% MVIC), and least with the sitting march right, crunch, and bent-knee sit-up exercises (7%-8% MVIC). Rectus femoris EMG signal was greatest with the hip extension left exercise (35% MVIC), and least with the crunch, roll-out, hip extension right, and decline push-up exercises (6%-10% MVIC). Lumbar paraspinal EMG signal was relative low (less than 10% MVIC) for all exercises., Conclusions: The roll-out and pike were the most effective exercises in activating upper and lower rectus abdominis, external and internal obliques, and latissimus dorsi muscles, while minimizing lumbar paraspinals and rectus femoris activity. J Orthop Sports Phys Ther 2010;40(5):265-276, Epub 22 April 2010. doi:10.2519/jospt.2010.3073.

Background and Purpose: Performing nontraditional abdominal exercises with devices such as abdominal straps, the Power Wheel, and the Ab Revolutionizer has been suggested as a way to activate abdominal and extraneous (nonabdominal) musculature as effectively as more traditional abdominal exercises, such as the crunch and bent-knee sit-up. The purpose of this study was to test the effectiveness of traditional and nontraditional abdominal exercises in activating abdominal and extraneous musculature., Subjects: Twenty-one men and women who were healthy and between 23 and 43 years of age were recruited for this study., Methods: Surface electromyography (EMG) was used to assess muscle activity from the upper and lower rectus abdominis, external and internal oblique, rectus femoris, latissimus dorsi, and lumbar paraspinal muscles while each exercise was performed. The EMG data were normalized to maximum voluntary muscle contractions. Differences in muscle activity were assessed by a 1-way, repeated-measures analysis of variance., Results: Upper and lower rectus abdominis, internal oblique, and latissimus dorsi muscle EMG activity were highest for the Power Wheel (pike, knee-up, and roll-out), hanging knee-up with straps, and reverse crunch inclined 30 degrees. External oblique muscle EMG activity was highest for the Power Wheel (pike, knee-up, and roll-out) and hanging knee-up with straps. Rectus femoris muscle EMG activity was highest for the Power Wheel (pike and knee-up), reverse crunch inclined 30 degrees, and bent-knee sit-up. Lumbar paraspinal muscle EMG activity was low and similar among exercises., Discussion and Conclusion: The Power Wheel (pike, knee-up, and roll-out), hanging knee-up with straps, and reverse crunch inclined 30 degrees not only were the most effective exercises in activating abdominal musculature but also were the most effective in activating extraneous musculature. The relatively high rectus femoris muscle activity obtained with the Power Wheel (pike and knee-up), reverse crunch inclined 30 degrees, and bent-knee sit-up may be problematic for some people with low back problems.

PURPOSE: Exercises that strengthen hip and thigh musculature, such as the forward lunge, are important to enhance patellofemoral joint stability in rehabilitation and training. The objective was to assess how patellofemoral joint force and stress change while lunging with step length and step height variations. The hypothesis was that patellofemoral force and stress would be greater with a short step and a ground-level step. METHODS: Sixteen participants performed a bodyweight forward lunge using short and long steps both at ground level and up to a 10 cm platform. Electromyography, ground reaction force, and kinematic variables were collected and input into a biomechanical optimization model, and patellofemoral joint force and stress were calculated as a function of knee angle. A repeated measures 2-way ANOVA (p < 0.05) with Holm-Bonferroni sequential correction was employed. RESULTS: No interactions between step length and step height were found. Comparing forward lunge with long step to short step, patellofemoral force and stress in the lead knee were greater with long step at the beginning of landing (10° to 30° knee angle) and the end of push-off (10° to 40° knee angle) and greater with short step during the deep knee flexion portion of the lunge (50° to 100° knee angle). Comparing forward lunge at ground level to a 10 cm platform, patellofemoral joint force and stress were greater at ground level during lunge descent (50° to 100° knee angle) and lunge ascent (40º to 70° knee angle). Patellofemoral joint force and stress generally increased as knee flexion increased and decreased as knee flexion decreased. CONCLUSIONS: Patellofemoral joint loading in the forward lunge change as step length, step height, and knee angle change. To gradually increase patellofemoral joint force and stress, it may be prudent to progress forward lunges as follows: 1) initially, with minimal knee flexion (0° to 30°); 2) then, with moderate knee flexion (0° to 60°); 3) with long step and deep knee flexion (0° to 100°) up to a 10 cm platform 4) and finally, with long step and deep knee flexion (0° to 100°) at ground level. [ABSTRACT FROM AUTHOR]

Background: Although weight bearing lunge exercises are frequently employed during anterior cruciate ligament and posterior cruciate ligament rehabilitation, cruciate ligament tensile forces are currently unknown while performing forward and side lunge exercises with and without a stride. Methods: Eighteen subjects used their 12 repetition maximum weight while performing a forward lunge and side lunge with and without a stride. A motion analysis system and biomechanical model were used to estimate cruciate ligament forces during lunging as a function of 0–90° knee angles. Findings: Comparing the forward lunge to the side lunge across stride variations, mean posterior cruciate ligament forces ranged between 205 and 765N and were significantly greater (P <0.0025) in the forward lunge long at 40°, 50°, 60°, 70°, and 80° knee angles of the descent phase and at 80°, 70°, 60° knee angles of the ascent phase. There were no significant differences (P <0.0025) in mean posterior cruciate ligament forces between with and without stride differences across lunging variations. There were no anterior cruciate ligament forces quantified while performing forward and side lunge exercises. Interpretation: Clinicians should be cautious in prescribing forward and side lunge exercises during early phases of posterior cruciate ligament rehabilitation due to relatively high posterior cruciate ligament forces that are generated, especially during the forward lunge at knee angles between 40° and 90° knee angles. Both the forward and side lunges appear appropriate during all phases of anterior cruciate ligament rehabilitation. Understanding how forward and side lunging affect cruciate ligament loading over varying knee angles may help clinicians better prescribe lunging exercises in a safe manner during anterior cruciate ligament and posterior cruciate ligament rehabilitation. [Copyright &y& Elsevier]