Study Design: A repeated-measures, counterbalanced design. Objectives: To test whether subjects could learn and retain the ability to alter the relative activity of abdominal muscle groups when performing trunk curl exercises. Background: Although trunk curl exercises are widely prescribed, a disadvantage of trunk curls is that they primarily activate rectus abdominis, while the internal and external oblique abdominis muscles are considered to be more important contributors to lumbar stability. Methods and Measures: A convenience sample of 25 subjects performed trunk curl exercises in accordance with 3 different sets of instructions: nonspecific instructions (NS), instructions intended to emphasize rectus abdominis activity (RE), and instructions intended to emphasize oblique abdominis activity (OE). Electromyographic (EMG) activity was recorded from the upper and lower rectus and the internal and external oblique abdominis muscles while a physical target was used to insure that the trunk was raised to the same height for all conditions. Normalized root-mean-square EMG amplitude measures were used to test for instruction-dependent changes in the relative EMG activity of the rectus and oblique muscle groups. Results: Following a single, brief, instruction session, subjects performing trunk curls had significantly greater normalized oblique:rectus EMG ratios when following OE instructions (mean [±SD] oblique-rectus ratio, 1.45 ± 0.34) than when following RE (mean [±SD] oblique-rectus ratio, 0.76 ± 0.24) or NS (mean [±SD] oblique-rectus ratio, 0.63 ± 0.23) instructions. Retesting 1 week later indicated that subjects retained this skill. Conclusions: With minimal instruction, subjects are able to volitionally alter the relative activity of the oblique and rectus abdominis muscles when performing trunk curls. Incorporating instructions emphasizing oblique abdominis activity into lumbar stabilization programs appears promising and has potential advantages over other approaches to altering abdominal muscle activity during trunk curls.

J Orthop Sports Phys Ther. 2004;34(1):4-12. doi:10.2519/jospt.2004.1145

Key Words: electromyography, lumbar spine, lumbar stabilization, rehabilitation

Study Design: A case series. Objectives: The purpose of this case series was to assess the effect of high-intensity neuromuscular electrical stimulation (NMES) on quadriceps strength and voluntary activation following total knee arthroplasty (TKA). Background: Following TKA, patients exhibit long-term weakness of the quadriceps and diminished functional capacity compared to age-matched healthy controls. The pain and swelling that results from surgery may contribute to quadriceps weakness. The use of high-intensity NMES has previously been shown to be effective in quickly restoring quadriceps strength in patients with weakness after surgery. Methods and Measures: All patients were treated for 6 weeks, 2 to 3 visits per week, in outpatient rehabilitation. Five patients (NMES group) participated in a voluntary exercise program for both knees and NMES for the weaker knee. Three patients (exercise group) participated in a voluntary exercise program for both knees without NMES. For each treatment session, 10 isometric electrically elicited muscle contractions were administered at maximally tolerated doses to the initially weaker leg of the NMES group. Quadriceps strength and muscle activation were repeatedly assessed up to 6 months after surgery using burst superimposition techniques. Results: At 6 months, the weak NMES-treated legs of 4 of 5 patients in the NMES group had surpassed the strength of the contralateral leg. In contrast, none of the weak legs in the exercise group were stronger than the contralateral leg at 6 months. Changes in quadriceps muscle activation mirrored the changes exhibited in strength. Conclusion: When NMES was added to a voluntary exercise program, deficits in quadriceps muscle strength and activation resolved quickly after TKA.

J Orthop Sports Phys Ther. 2004;34(1):21-29. doi:10.2519/jospt.2004.0947

Key Words: geriatric, inhibition, rehabilitation, total knee replacement

February 4-8, 2004 Nashville, Tennessee

A summary of the schedule of platform and poster research presentations made by the Orthopaedic Section and Sports Physical Therapy Section of the American Physical Therapy Association during APTA’s Combined Sections Meeting.

J Orthop Sports Phys Ther. 2004;34(1):31-38.

The abstracts are presented here as prepared by the authors. The accuracy and content of each abstract remain the responsibility of the authors. In the identification number above each abstract, PO designates a poster presentation. The presenter’s name is underlined where that information was available to the JOSPT. (PO258 withdrawn.)

J Orthop Sports Phys Ther. 2004;34(1):A23-A51.

The abstracts are presented here as prepared by the authors. The accuracy and content of each abstract remain the responsibility of the authors. In the identification number above each abstract, PO designates a poster presentation. The presenter’s name is underlined where that information was available to the JOSPT.

J Orthop Sports Phys Ther. 2004;34(1):A61-A65.