Influence of external fixation on the isomeric strength of the shoulder flexors in individuals with scapular elevation.

BACKGROUND: Sufficient shoulder flexor strength is necessary for accurate movement of the shoulder joint because several factors can cause compensatory movements of the scapula. OBJECTIVE: We investigated the influence of external fixation on the isometric shoulder flexors strength (ISFS) in individuals with and without scapular elevation (SE) during shoulder flexion. METHODS: The healthy and SE groups included 29 individuals. The ISFS was measured using a tensiometer (kg) under conditions of with and without external fixation, in a random order. The change in the ISFS (the strength difference with and without external fixation) was compared between the healthy and SE groups using an independent t-test. RESULTS: The change in the ISFS differed significantly between the healthy and SE groups (3.5% and 32.3%, respectively; p= 0.001). CONCLUSION: These findings suggest that external fixation should be considered during shoulder flexion to determine the ISFS accurately in individuals with compensated SE.

Effects of pelvic tilt control using visual biofeedback on gluteus maximus, multifidus, and hamstring activities during three different bridge exercises.

BACKGROUND: The effects of pelvic tilt control using visual biofeedback on gluteus maximus (GM), multifidus (MF), and hamstring (HAM) muscle activities during bridge exercises involving anterior pelvic tilt (APT), neutral pelvic tilt (NPT), and posterior pelvic tilt (PPT) were investigated. METHODS: Twenty-five healthy participants were included (mean age, 24.6 ± 1.9 years). Visual biofeedback was used for the participants to self-control pelvic tilt during the bridge exercises. Pelvic tilt controls were performed in a random order (APT vs. NPT vs. PPT) following 30 minutes education program. GM, MF, and HAM muscle activities were measured by surface electromyography. One-way repeated analysis of variance and Bonferroni post hoc test were used. RESULT: GM and MF muscle activities significantly differed among the different pelvic tilting controls (APT vs. NPT vs. PPT) (p < .017). GM muscle activity during the exercise involving PPT was significantly higher than that involving APT and NPT (p < .017). In contrast, MF muscle activity during the exercise involving PPT was significantly lower than that involving APT (p < .017). In addition, the GM/Right MF, GM/Left MF, and GM/HAM muscle activity ratios during the exercise involving PPT were significantly greater than those involving APT and NPT (p < .017). CONCLUSIONS: The bridge exercise involving PPT using visual biofeedback can be recommended as a home exercise to selectively improve the muscle activity of the GM and the muscle activity ratio of the GM/HAM and GM/MF. This information may be valuable for clinicians seeking exercise programs to target specific muscles effectively.

Effects of vibration-based biofeedback on multifidus muscle activity and pelvic tilt angle in subjects with hip flexion limitation.

BACKGROUND: Sedentary work may lead to low back pain. In particular, a slumped sitting position may exacerbate low back pain because of tissue damage caused by excessive lumbar flexion and posterior pelvic tilting. Subjects with low back pain may have excessive changes in the lumbopelvic posture and back muscle activity in the sitting position. OBJECTIVE: The purpose of this study was to compare the effects of vibration-based biofeedback using a motion sensor belt and no biofeedback on multifidus (MF) muscle activity and pelvic tilt angle during typing. METHODS: Thirty subjects with low back pain accompanied by hip flexion limitation (15 each in the biofeedback and non-biofeedback groups) were enrolled. Electromyography was used to investigate MF muscle activity before and after typing for 30 min. Pelvic tilt was measured after typing in a sitting position for 30 min. Independent t-tests were used to compare MF muscle activity, and pelvic and second sacrum tilt angles, between the biofeedback and non-biofeedback groups. RESULTS: After typing for 30 min, changes in MF muscle activity (11.45% and -7.19% for the biofeedback and nonbiofeedback groups, respectively) and pelvic and second sacrum tilt angles (3.15∘ and 4.12∘ for the biofeedback group and -11.05∘ and -18.16∘ for the non-biofeedback group, respectively) were significantly smaller in the biofeedback than non-biofeedback group (p< 0.05). CONCLUSION: Vibration-based biofeedback minimizes the reduction in MF muscle activity and changes in pelvic and second sacrum tilt angles during typing in individuals with low back pain accompanied by hip flexion limitation.

Comparison of abductor hallucis muscle activity in subjects with mild hallux valgus during three different foot exercises.

BACKGROUND: Normal alignment of the foot is important because the feet support the body's weight. The intrinsic muscles of the foot mainly maintain the alignment and movement of the foot, whereas the abductor hallucis (AbdH) aligns the first metatarsophalangeal joint and maintains the medial longitudinal arch. OBJECTIVE: This study was conducted to investigate the muscle activity of the AbdH and hallux valgus (HV) angle during three different foot exercises. METHODS: Participants included 15 subjects aged 20-24 years with mild HV. All subjects performed three different foot exercises in random order: short foot exercise (SF), toe spread out exercise (TSO), and TSO with a pressure bio-feedback unit (TSOP). The muscle activity of the AbdH and the HV angle were measured during each foot exercise using surface electromyography and X-ray and then compared using one-way repeated-measures analysis of variance, followed by Bonferroni adjustment. RESULTS: AbdH muscle activity differed significantly among SF, TSO, and TSOP. AbdH muscle activity was greater in TSOP (89.60%) than in SF (19.99%) and TSO (60.96%) (p= 0.006). The HV angle was significantly smaller in TSOP (15.72∘) than in SF (18.85∘) and TSO (16.81∘) (p= 0.001). CONCLUSIONS: TSOP can be recommended as an effective AbdH strengthening exercise in subjects with mild HV.

Effects of abdominal drawing-in maneuver with or without prior iliopsoas stretching on gluteus maximus activity during prone hip extension.

BACKGROUND: Prone hip extension (PHE) has been investigated to strengthen the hip joint and back extensor muscles. However, it has not been compared with various PHE exercises in individuals with iliopsoas shortness. OBJECTIVE: This study compared pelvic compensation and hip and back extensor muscle activities in individuals with iliopsoas shortness during prone hip extension (PHE) using the abdominal drawing-in maneuver alone (PHEA) and after iliopsoas stretching (PHEAS). METHODS: Twenty-five individuals with iliopsoas shortness were included in the study. Electromyography was used to investigate bilateral erector spinae (ES) and ipsilateral gluteus maximus (GM), biceps femoris (BF), and semitendinosus (ST) muscles during PHE, PHEA, and PHEAS. Pelvic anterior tilting and rotation angles were measured during each PHE exercise via electromagnetic motion tracking. A modified Thomas test was used to examine the hip extension angle before and after iliopsoas stretching. One-way repeated-measures analysis of variance was used to investigate differences in pelvic anterior tilting and rotation angle and in hip and back extensor muscle activities among PHE, PHEA, and PHEAS. The level of statistical significance was set at α= 0.01. RESULTS: GM muscle activity was significantly greater with PHEAS, compared to PHE and PHEA (p< 0.01). Bilateral ES and ipsilateral BF and ST muscle activities were significantly reduced with PHEAS, compared to PHE and PHEA (p< 0.01). Anterior pelvic tilting and rotation angles were significantly reduced with PHEAS, compared to PHE and PHEA (p< 0.01). CONCLUSIONS: PHEAS is recommended to selectively strengthen GM muscles with minimal BF and ST muscle activities and pelvic compensation in individuals with iliopsoas shortness. The abdominal drawing-in maneuver (ADIM) after iliopsoas stretching is more efficient than ADIM alone during PHE, especially in individuals with iliopsoas shortness.

Comparison of the electromyographic recruitment of the posterior oblique sling muscles during prone hip extension among three different shoulder positions.

Objective: We examined the effects of three different shoulder positions on the electromyography (EMG) activity of the posterior oblique sling and pelvic rotational angle during right prone hip extension (PHE).Methods: Fifteen healthy males (mean age, 25.4 ± 1.2 years) participated in this study. Three different left shoulder positions (0°, 90°, 125° of abduction) were assessed during right PHE. Surface EMG signals were recorded for the left latissimus dorsi, left middle trapezius, left lower trapezius, lumbar multifidus, right gluteus maximus, and right biceps femoris. An electromagnetic tracking motion analysis device was used to monitor compensatory pelvic rotation during right PHE. Significant differences in muscle activity and pelvic rotation angle among the three different shoulder abductions were assessed using one-way repeated measures analysis of variance and the Bonferroni post hoc test.Results: The bilateral multifidus and right gluteus maximus EMG amplitudes increased with increasing shoulder abduction angle during PHE (padj < 0.01). The degree of pelvic rotation during PHE decreased with increasing shoulder abduction angle (padj < 0.01).Conclusions: We found that PHE with 125° of left shoulder abduction increased the selective activation of lumbopelvic stabilizing muscles such as the multifidus and gluteus maximus.

Effect of applying consistent pressure to the stationary and the moving arm on measurement reliability of glenohumeral internal rotation range of motion.

OBJECTIVES: The aim of this study was to determine the inter-rater reliability of glenohumeral internal rotation (GIR) range of motion (ROM) and pressure measurements among four measurement methods: (1) Manual stabilization of the humeral head and coracoid process (MSHC) without applying consistent pressure (ACP) to both the stationary and the moving arms (BSaMA); (2) MSHC with ACP to the moving arm; (3) MSHC with ACP to the stationary arm; and (4) MSHC with ACP to BSaMA. DESIGN: Test-retest analyses. PARTICIPANTS: 39 subjects with GIR deficit. MAIN OUTCOME MEASURES: GIR ROM and pressure were measured on the stationary or moving arm by four examiners using the Clinometer application and a pressure biofeedback unit. RESULTS: GIR ROM measurement with MSHC and ACP to the moving arm resulted in the lowest intra-class correlation coefficient (ICC = .43); the ICC for MSHC without ACP to BSaMA was .54; that for MSHC with ACP to the stationary arm was .77; and that for MSHC with ACP to BSaMA was highest, at .81. CONCLUSION: MSHC with ACP to both arms leads to reliable GIR ROM measurement in a clinical setting.

Correlation between the distance of scapular anterior tilting and the ratio of internal and external rotation angle of shoulder in supine position.

[Purpose] This study investigated the relationship between the amount of scapular anterior tilting and the ratio of internal and external rotation of the shoulder in a supine position. [Participants and Methods] Twenty healthy participants (8 females, 12 males) were enrolled in this study. Internal rotation (IR) and external rotation (ER) of the glenohumeral joint were performed in a supine position, and the IR and ER angles were measured using a universal goniometer. The changing distance of scapular anterior tilting was measured by a three-dimensional motion analysis tracking system while participants performed IR and ER in a supine position. Pearson's correlation coefficient was used to investigate the relationship between the distance of scapular anterior tilting and the ratio of internal and external rotation angle of the shoulder. [Results] The correlation of the degree of scapular anterior tilting with the IR/ER ratio, particularly the IR angle of the shoulder in a supine position, was good to excellent (r=-0.851). [Conclusion] The findings suggest that asymmetry of the IR and ER angles may cause increased scapular anterior tilting in a supine position.

Effect of psoas major pre-activation on electromyographic activity of the abdominal muscles and pelvic rotation during active leg raising.

[Purpose] This study investigated the effect of psoas major pre-activation on the electromyographic (EMG) activity of the abdominal muscles and pelvic rotation during active leg raising (ALR). [Participants and Methods] Twenty healthy participants were enrolled. ALR was performed in a conventional manor or with contralateral psoas major (cPM) pre-activation. The EMG activity of the abdominal muscles, including the rectus abdominalis (RA), external oblique (EO), and internal oblique (IO), was measured, as was pelvic rotation. Paired t-tests were used. [Results] The EMG activity of all studied muscles was significantly increased, and pelvic rotation was significantly decreased, during ALR with psoas major pre-activation compared to the levels under conventional testing. [Conclusion] cPM pre-activation during ALR can increase abdominal muscle activity and minimize pelvic rotation.

Reliability and criterion validity of measurements using a smart phone-based measurement tool for the transverse rotation angle of the pelvis during single-leg lifting.

OBJECTIVE: The purposes of this study were to determine the intra-rater test-retest reliability of a smart phone-based measurement tool (SBMT) and a three-dimensional (3D) motion analysis system for measuring the transverse rotation angle of the pelvis during single-leg lifting (SLL) and the criterion validity of the transverse rotation angle of the pelvis measurement using SBMT compared with a 3D motion analysis system (3DMAS). METHOD: Seventeen healthy volunteers performed SLL with their dominant leg without bending the knee until they reached a target placed 20 cm above the table. This study used a 3DMAS, considered the gold standard, to measure the transverse rotation angle of the pelvis to assess the criterion validity of the SBMT measurement. Intra-rater test-retest reliability was determined using the SBMT and 3DMAS using intra-class correlation coefficient (ICC) [3,1] values. The criterion validity of the SBMT was assessed with ICC [3,1] values. RESULT: Both the 3DMAS (ICC = 0.77) and SBMT (ICC = 0.83) showed excellent intra-rater test-retest reliability in the measurement of the transverse rotation angle of the pelvis during SLL in a supine position. Moreover, the SBMT showed an excellent correlation with the 3DMAS (ICC = 0.99). CONCLUSION: Measurement of the transverse rotation angle of the pelvis using the SBMT showed excellent reliability and criterion validity compared with the 3DMAS.

An immediate effect of axial neck rotation training with real time visual feedback using a smartphone inclinometer on improvement in axial neck rotation function.

OBJECTIVES: The purpose of this study was to compare the immediate effects of axial neck rotation training (Axi-NRT) with and without real-time visual feedback (VF) using a smartphone inclinometer on the range of motion (ROM) for axial neck rotation and the onset of compensatory neck lateral bending and extension during active neck rotation. METHODS: Twenty participants with restricted ROM for neck rotation but no neck pain (21.1 ± 1.6 years and 8 males, 12 females) were recruited for Axi-NRT with VF, and twenty age- and gender-matched participants with restricted ROM for neck rotation were recruited for Axi-NRT without VF. Changes in ROM for neck rotation and the onset time of compensatory neck movement during active neck rotation were measured using an electromagnetic tracking system. RESULTS: Axi-NRT with VF was more effective in increasing ROM for neck rotation and decreasing and delaying the onset of compensatory neck movements during active neck rotation compared with Axi-NRT without VF. CONCLUSIONS: Repeated Axi-NRT using VF is useful to educate participants in maintaining the axis of the cervical spine and to increase ROM for axial neck rotation with less compensatory neck motion in participants with a restricted range of neck rotations.

Effect of Humeral-Elevation Angle on Electromyographic Activity in the Serratus Anterior During the Push-Up-Plus Exercise.

CONTEXT: The push-up-plus (PP) exercise has been recommended for strengthening of the serratus anterior (SA). Previous studies have investigated the effect of different stability properties of the base of support to adjust the difficulty level of SA muscle-strengthening exercises in the PP position. However, the optimal humeral-elevation angle (HEA) for selective activation and maximum contraction of the SA during PP has not been investigated. OBJECTIVES: To assess the effects of HEA during PP on electromyographic (EMG) activity in the SA, upper trapezius (UT), and pectoralis major (PM) and on the UT:SA and PM:SA activity ratios. DESIGN: Comparative, repeated-measures design. SETTING: University research laboratory. PARTICIPANTS: 29 healthy men. MAIN OUTCOME MEASURES: The subjects performed PP at 3 different HEAs (60°, 90°, and 120°); EMG activity in the SA, UT, and PM was measured, and the UT:SA and PM:SA activity ratios were calculated. Differences in muscle activity and ratios between the 60°, 90°, and 120° HEAs were assessed using 1-way repeated-measures analysis of variance; the Bonferroni correction was applied. RESULTS: SA muscle activity was significantly increased, in order of magnitude, at the 120°, 90°, and 60° HEAs. UT:SA and PM:SA activity ratios were significantly greater during performance of the PP at an HEA of 60° than at HEAs of 120° and 90°. CONCLUSION: The results suggest that an HEA of 120° should be used during performance of the PP because it produces greater SA activation than HEAs of 60° and 90°.

Comparison of Hip- and Back-Muscle Activity and Pelvic Compensation in Healthy Subjects During 3 Different Prone Table Hip-Extension Exercises.

CONTEXT: Prone hip extension has been recommended for strengthening the back and hip muscles. Previous studies have investigated prone hip extension conducted with subjects on the floor in the prone position. However, no study has compared 3 different table hip-extension (THE) positions in terms of the activities of the back- and hip-joint muscles with lumbopelvic motion. OBJECTIVE: To identify more effective exercises for strengthening the gluteus maximus (GM) by comparing 3 different exercises (THE alone, THE with the abdominal drawing-in maneuver [THEA], and THEA with chair support under the knee [THEAC]) based on electromyographic muscle activity and pelvic compensation. DESIGN: Repeated-measure within-subject intervention. SETTING: University research laboratory. PARTICIPANTS: 16 healthy men. MAIN OUTCOME MEASURES: Surface electromyography (EMG) was used to obtain data on the GM, erector spinae (ES), multifidus, biceps femoris (BF), and semitendinosus (ST). Pelvic compensation was monitored using an electromagnetic motion-tracking device. Exertion during each exercise was recorded. Any significant difference in electromyographic muscle activity and pelvic motion among the 3 conditions (THE vs THEA vs THEAC) was assessed using a 1-way repeated-measures analysis of variance (ANOVA) with Bonferroni post hoc test. RESULTS: The muscle activities recorded by EMG differed significantly among the 3 exercises (P < .01). GM activity was increased significantly during THEAC (P < .01). There was a significant difference in lumbopelvic kinematics in terms of anterior tilting (F = 19.49, P < .01) and rotation (F= 27.38, P < .01) among the 3 exercises. CONCLUSIONS: The THEAC exercise was the most effective for strengthening the GM without overactivity of the ES, BF, and ST muscles and lumbopelvic compensation compared with THE and THEA.

Comparison of gluteus maximus and hamstring electromyographic activity and lumbopelvic motion during three different prone hip extension exercises in healthy volunteers.

OBJECTIVE: To compare the surface electromyography (EMG) amplitude of the hip joint, including the gluteus maximus (GM), biceps femoris (BF), and semitendinosus (ST) muscles generated by three different exercises: prone hip extension (PHE), prone table hip extension (PTHE), and prone table hip extension with 90° knee flexion (PTHEK), with compensatory pelvic motions. DESIGN: Repeated-measure within-subject intervention. PARTICIPANTS: Sixteen-healthy males (mean age = 23.4 ± 2.2 years). MAIN OUTCOME MEASURES: EMG was used to collect EMG signals from the GM, erector spinae (ES), BF, and ST muscles. Furthermore an electromagnetic tracking motion analysis was also performed to measure the compensations. RESULTS: EMG amplitude differed significantly among the three conditions (PHE vs. PTHE vs. PTHEK) (p < 0.05). The mean GM muscle activity increased significantly during the PTHEK (70.93% and 13.75% increases in %MVIC compared with the PHE and PTHE, respectively) (p < 0.01). However, there was no significant difference in the kinematic data for rotation or anterior tilting angle of the pelvis among the three conditions (p > 0.05). CONCLUSIONS: These results suggest that the PTHEK can be recommended as an effective method to strengthen the GM muscle without increased BF or ES muscle activities and without compensatory pelvic motions.

Comparison of psoas major muscle thickness measured by sonography during active straight leg raising in subjects with and without uncontrolled lumbopelvic rotation.

BACKGROUND: The psoas major (PM) is important for stabilizing lumbopelvic region during active straight leg raising (ASLR). Uncontrolled lumbopelvic rotation (ULPR) frequently occurs during ASLR in subjects with poor lumbo-pelvic stability and may contribute to asymmetric symptoms including pain in lumbopelvic region. OBJECTS: This study compared the thickness of contralateral PM (cPM) using ultrasound imaging during ASLR in subjects with and without ULPR. METHOD: Healthy male subjects (18 without ULPR, 19 with ULPR) were recruited. The thickness of the cPM during rest and ASLR without loading and with a 1-kg load was measured by ultrasound imaging. The relative muscle thickness was calculated as the thickness during ASLR/thickness at rest. Two-way mixed-model analysis of variance was used to identify significant differences in the relative thickness of the cPM between groups and within a loading status. The level of statistical significance was set at α = 0.05. RESULTS: The resting thickness of the cPM in subjects without ULPR did not differ from that of subjects with ULPR. The relative thickness of the cPM in subjects without ULPR was significantly greater during ASLR than that in subjects with ULPR both without loading and with a load (p < 0.01). No significant change in thickness of the cPM was evident in those with ULPR. CONCLUSION: The thickness of the cPM was significantly greater during ASLR in subjects without ULPR than with ULPR. This result indicates that persons with ULPR have less activation of the cPM to stabilize the lumbar spine during ASLR.

Reliability of ultrasonography measurement for the longus colli according to inward probe pressure.

[Purpose] To investigate the intra- and inter-rater reliability of the cross-sectional area (CSA) and muscle thickness (MT) of the longus colli according to the inward pressure of an ultrasonography (US) probe (0.5 and 1 kg). [Subjects] Thirteen subjects (11 males and 2 females; age, 23.1 ± 2.9 years) were recruited via convenience sampling of university students. [Methods] Real-time US measurements of the CSA and MT of the longus colli were recorded. Repeated US measurements using a standard protocol were performed on the same day 1 hour apart to assess intra- and inter-rater reliability. Intra-class correlation coefficients (ICC; 2, 1) were used to determine the intra- and inter-rater reliability of the CSA and MT measurements. [Results] This study demonstrated that the US measurements (0.5 and 1 kg) of the CSA and MT of the longus colli give reliable and consistent results. [Conclusion] Based on these results, a consistent inward pressure of the probe is needed to ensure precise US measurement of the longus colli muscle.

Ankle-Dorsiflexion Range of Motion After Ankle Self-Stretching Using a Strap.

CONTEXT: A variety of ankle self-stretching exercises have been recommended to improve ankle-dorsiflexion range of motion (DFROM) in individuals with limited ankle dorsiflexion. A strap can be applied to stabilize the talus and facilitate anterior glide of the distal tibia at the talocrural joint during ankle self-stretching exercises. Novel ankle self-stretching using a strap (SSS) may be a useful method of improving ankle DFROM. OBJECTIVE: To compare the effects of 2 ankle-stretching techniques (static stretching versus SSS) on ankle DFROM. DESIGN: Randomized controlled clinical trial. SETTING: University research laboratory. PATIENTS OR OTHER PARTICIPANTS: Thirty-two participants with limited active dorsiflexion (<20°) while sitting (14 women and 18 men) were recruited. MAIN OUTCOME MEASURE(S): The participants performed 2 ankle self-stretching techniques (static stretching and SSS) for 3 weeks. Active DFROM (ADFROM), passive DFROM (PDFROM), and the lunge angle were measured. An independent t test was used to compare the improvements in these values before and after the 2 stretching interventions. The level of statistical significance was set at α = .05. RESULTS: Active DFROM and PDFROM were greater in both stretching groups after the 3-week interventions. However, ADFROM, PDFROM, and the lunge angle were greater in the SSS group than in the static-stretching group (P < .05). CONCLUSIONS: Ankle SSS is recommended to improve ADFROM, PDFROM, and the lunge angle in individuals with limited DFROM.

Lower extremity strength and the range of motion in relation to squat depth.

The purpose of this study was to determine which variables of the range of motion (ROM) and strength of the hip, and ankle are associated with squat depth. In total, 101 healthy subjects (64 males, 37 females) participated in the study. Outcome measures consisted of the ROM of hip flexion, hip internal rotation, external rotation, ankle dorsiflexion with an extended and flexed knee joint, and strength of the hip flexor and ankle dorsiflexor. Squat depth was measured using SIMI motion analysis software. Pearson correlation was used to determine the relationship between variables and squat depth. Multiple stepwise regression analysis was performed to determine variables associated with squat depth. The multiple regression model indicated that ankle dorsiflexion with a flexed knee and the hip flexion ROM were significantly associated with squat depth in male subjects (R(2) = 0.435) and ankle dorsiflexion with an extended knee and dorsiflexor strength were significantly associated with squat depth in female subjects (R(2) = 0.324). Thus, exercises to increase the ROM of the ankle dorsiflexion, hip flexion, and dorsiflexor strength can be recommended to improve squat performance. Future studies should assess an increased ROM of the ankle dorsiflexion, hip flexion, or dorsiflexor strength effect on deep squat performance.

Effect of treadmill walking with ankle stretching orthosis on ankle flexibility and gait.

[Purpose] The purpose of this study was to evaluate the kinematics of the ankle in the lunge to estabilish effectiveness of an ankle stretching orthosis (ASO) on the ankle dorsiflexion range of motion (ROM) of individuals with limited dorsiflexion ROM. [Subjects and Methods] Forty ankles with decreased dorsiflexion ROM of 20 participants were evaluated in this study. After wearing the ASO, participants walked on a treadmill for 15 minutes. Participants walked on the treadmill at a self-selected comfortable speed. Ankle dorsiflexion ROM, maximum dorsiflexion ROM before heel-off, and time to heel-off during the stance phase of gait were measured before and after 15 minutes of treadmill walking with the ASO. The differences in all variables between before and after treadmill walking with ASO were analyzed using the paired t-test. [Results] Ankle active and passive ROM, and dorsiflexion ROM during lunge increased significantly after treadmill walking with ASO. Treadmill walking with the ASO significantly increased the angle of maximal dorsiflexion before heel-off and time to heel-off during the stance phase. [Conclusion] The results of this study show that treadmill walking with the ASO effectively improved ankle flexibility and restored the normal gait pattern of the ankle joint by increasing dorsiflexion ROM, maximal angle of dorsiflexion, and time to heel-off in the stance phase.

The effects of surface condition on abdominal muscle activity during single-legged hold exercise.

To treat low-back pain, various spinal stability exercises are commonly used to improve trunk muscle function and strength. Because human movement for normal daily activity occurs in multi-dimensions, the importance of exercise in multi-dimensions or on unstable surfaces has been emphasized. Recently, a motorized rotating platform (MRP) for facilitating multi-dimensions dynamic movement was introduced for clinical use. However, the abdominal muscle activity with this device has not been reported. The purpose of this study was to compare the abdominal muscle activity (rectus abdominis, external and internal oblique muscles) during an active single-leg-hold (SLH) exercise on a floor (stable surface), foam roll, and motorized rotating platform (MRP). Thirteen healthy male subjects participated in this study. Using electromyography, the abdominal muscle activity was measured while the subjects performed SLH exercises on floor (stable surface), foam roll, and MRP. There were significant differences in the abdominal muscle activities among conditions (P<.05), except for left EO (P>.05) (Fig. 2). After the Bonferroni correction, however, no significant differences among conditions remained, except for differences in both side IO muscle activity between the floor and foam roll conditions (padj<0.017). The findings suggest that performing the SLH exercises on a foam roll and MRP is more effective increased activities of both side of RA and IO, and Rt. EO compared to floor condition. However, there were no significant differences in abdominal muscles activity in the multiple comparison between conditions (mean difference were smaller than the standard deviation in the abdominal muscle activities) (padj>0.017), except for differences in both side IO muscle activity between the floor (stable surface) and foam roll (padj<0.017) (effect size: 0.79/0.62 (non-supporting/supporting leg) for foam-roll versus floor).