Comparison of EMG activity between maximal manual muscle testing and cybex maximal isometric testing of the quadriceps femoris

Inter-rater and intra-rater reliability of isotonic exercise monitoring device for measuring active knee extension

Background

The goal of this study was to assess the reliability of electromyography and range of motion measurements obtained using a knee exercise monitoring system. This device was developed to collect data on knee exercise activities.

Methods

Twenty healthy individuals performed isotonic quadriceps exercises in this study. The vastus medialis surface electromyography (sEMG) and range of motion (ROM) of the knee were recorded during the exercise using the isotonic knee exercise monitoring device, the Mobi6-6b, and a video camera system. Each subject underwent a second measuring session at least 24 h after the first session. To determine reliability, the intraclass correlation coefficients (ICCs) and standard error of measurement (SEM) at the 95% confidence interval were calculated, and a Bland-Altman analysis was performed.

Results

For inter-rater reliability, the ICCs of the mean absolute value (MAV) and root mean square (RMS) of sEMG were 0.73 (0.49, 0.86) and 0.79 (0.61, 0.89), respectively. ROM had an ICC of 0.93 (0.02, 0.98). The intra-rater reliability of the MAV of the sEMG was 0.89 (0.71, 0.96) and the intra-rater reliability of RMS of the sEMG was 0.88 (0.70, 0.95). The ROM between days had an intra-rater reliability of 0.82 (0.54, 0.93). The Bland-Altman analysis demonstrated no systematic bias in the MAV and RMS of sEMG, but revealed a small, systematic bias in ROM (-0.8311 degrees).

Conclusion

For sEMG and range of motion measures, the isotonic knee exercise monitoring equipment revealed moderate to excellent inter- and intra-rater agreement. However, the confidence interval of ROM inter-rater reliability was quite large, indicating a small agreement bias; hence, the isotonic knee exercise monitor may not be suitable for measuring ROM. This isotonic knee exercise monitor could detect and collect information on a patient's exercise activity for the benefit of healthcare providers.

Differences in the muscle activities of the quadriceps femoris and hamstrings while performing various squat exercises

Background

Knee injuries in the lower limbs frequently occur, and lower limb muscles need to be strengthened to reduce injuries. Activating muscles can help strengthen muscles.. This study aimed to determine the squat exercises [general squat (GS), wall squat (WS), and Spanish squat (SS)] that effectively increased muscle activity using electromyography (EMG).

Methods

In this cross-sectional study, 22 participants performed three different squat exercises with EMG attached to the rectus femoris (RF), vastus lateralis (VL), vastus medialis, biceps femoris, semitendinosus, and semimembranosus. The Kruskal–Wallis H test was used to compare thigh muscle activities among the various squat exercises.

Results

During SS, RF showed greater muscle activation compared to WS and GS (RF: χ2 = 21.523, p = 0.000, η² = 0.333). VL also showed greater muscle activation during SS compared to WS (VL: χ2 = 7.101, p = 0.029, η² = 0.109).

Conclusions

The results from this study indicate that SS shows more activation in the RF and VL muscles compared to GS and WS. These findings suggest that SS can provide more muscle activation for the RF and VL muscles and will greatly help those who lack muscle activation in these muscles.

Electromyographic study of hip muscles involved in total hip arthroplasty: Surprising results using the direct anterior minimally invasive approach

BACKGROUND

The functional and clinical benefit of minimally invasive total hip arthroplasty (THA) is well-known, but the literature reports impaired gait and posture parameters as compared to the general population, especially following use of the anterior minimally invasive approach, which has more severe impact on posture than the posterior approach. The reasons for this impairment, however, remain unexplained. We therefore conducted a surface electromyography (sEMG) study of the hip muscles liable to be affected by arthroplasty surgery: gluteus maximus (GMax), gluteus medius (GMed), tensor fasciae latae (TFL), and sartorius (S). The study addressed the following questions: (1) Is bipodal and unipodal GMed activity greater following anterior THA than in asymptomatic subjects? (2) Is a single manual test sufficient to assess maximal voluntary contraction (MVC) in hip abductors (GMax, GMed, TFL) and flexors (TFL, S)?

HYPOTHESIS

Bipodal and unipodal GMed activity is greater following anterior THA than in asymptomatic subjects.

METHOD

Eleven patients with anterior THA and 11 asymptomatic subjects, matched for age, gender and body-mass index, were included. Subjects underwent 3 postural tests: bipodal, eyes closed (BEC), unipodal on the operated side (UOP), and unipodal on the non-operated side (UnOP), with unipodal results averaged between both sides in the asymptomatic subjects. Data were recorded from 4-channel EMG and a force plate. EMG test activity was normalized as a ratio of MVC activity.

RESULTS

Postural parameters (mean center of pressure displacement speed) were poorer and sEMG activity higher in anterior THA than asymptomatic subjects (p<0.005). On the BEC test, GMax and GMed activity was higher on both operated and non-operated sides than in asymptomatic controls (respectively, 0.15±0.12 and 0.12±0.6 versus 0.07±0.06 for GMax, and 0.13±0.08 and 0.13±0.08 versus 0.08±0.05 for GMed; p<0.05). On unipodal tests, both UOP and UnOP GMed activities were higher than in controls (respectively, 0.51±0.3 and 0.48±0.27 versus 0.28±0.13; p<0.04); GMax and TFL activities were higher than in controls only on the UOP tests (respectively, 0.49±0.43 versus 0.24±0.18, and 0.23±0.17 versus 0.12±0.16; p<0.05).

DISCUSSION

sEMG activity in the hip abductors, which are the main stabilizing muscles for the pelvis, is increased following anterior THA, in parallel with impaired postural parameters. This finding may be due to intraoperative TFL and S neuromuscular spindle lesion. The present preliminary study is to be followed up by a comparison of all 3 common minimally invasive approaches (anterior, anterolateral and posterior) using the same study protocol.

LEVEL OF EVIDENCE

III, prospective case-control study.

The effect of different hip rotation angles on electromyography activity of the quadriceps muscle during closed kinetic chain tasks in healthy females

[Purpose] The purpose of this study was to investigate electromyographic activity of the quadriceps muscle in different positions of hip rotation (while standing on the toes) in healthy females. [Participants and Methods] The study was conducted on 35 healthy females. Electromyographic activity of the rectus femoris, vastus medialis oblique, and vastus lateralis muscles were recorded with the hip in a neutral position as well as different angles of internal and external rotation (15, 30, and 45 degrees (°)) while the participants were standing on their toes. [Results] There was a significant difference of 15° in external rotation, a neutral position, 15° of internal rotation, and at the end of an internal rotation position. Paired comparison between muscle activity using Bonferroni showed that vastus lateralis activity in 15° of external rotation, a neutral position, 15° of internal rotation, and at the end of a position of internal rotation was more than that of rectus femoris muscle. [Conclusion] The present study showed that average vastus lateralis activity was the highest in all positions. However, the positions studied in the current study did not lead to an increase in muscle activity of the vastus medialis oblique as a medial dynamic stabilizer compared to vastus lateralis.

Does hip joint positioning affect maximal voluntary contraction in the gluteus maximus, gluteus medius, tensor fasciae latae and sartorius muscles?

BACKGROUND

Minimally invasive total hip arthroplasty (THA) is presumed to provide functional and clinical benefits, whereas in fact the literature reveals that gait and posturographic parameters following THA do not recover values found in the general population. There is a significant disturbance of postural sway in THA patients, regardless of the surgical approach, although with some differences between approaches compared to controls: the anterior and anterolateral minimally invasive approaches seem to be more disruptive of postural parameters than the posterior approach. Electromyographic (EMG) study of the hip muscles involved in surgery [gluteus maximus (GMax), gluteus medius (GMed), tensor fasciae latae (TFL), and sartorius (S)] could shed light, the relevant literature involves discordant methodologies. We developed a methodology to assess EMG activity during maximal voluntary contraction (MVC) of the GMax, GMed, TFL and sartorius muscles as a reference for normalization. A prospective study aimed to assess whether hip joint positioning and the learning curve on an MVC test affect the EMG signal during a maximal voluntary contraction.

HYPOTHESIS

Hip positioning and the learning curve on an MVC test affect EMG signal during MVC of GMax, GMed, TFL and S.

METHODS

Thirty young asymptomatic subjects participated in the study. Each performed 8 hip muscle MVCs in various joint positions recorded with surface EMG sensors. Each MVC was performed 3 times in 1 week, with the same schedule every day, controlling for activity levels in the preceding 24h. EMG activity during MVC was expressed as a ratio of EMG activity during unipedal stance. Non-parametric tests were applied.

RESULTS

Statistical analysis showed no difference according to hip position for abductors or flexors in assessing EMG signal during MVC over the 3 sessions. Hip abductors showed no difference between abduction in lateral decubitus with hip straight versus hip flexed: GMax (19.8±13.7 vs. 14.5±7.8, P=0.78), GMed (13.4±9.0 vs. 9.9±6.6, P=0.21) and TFL (69.5±61.7 vs. 65.9±51.3, P=0.50). Flexors showed no difference between hip flexion/abduction/lateral rotation performed in supine or sitting position: TFL (70.6±45.9 vs. 61.6±45.8, P=0.22) and S (101.1±67.9 vs. 72.6±44.6, P=0.21). The most effective tests to assess EMG signal during MVC were for the hip abductors: hip abduction performed in lateral decubitus (36.7% for GMax, 76.7% for GMed), and for hip flexors: hip flexion/abduction/lateral rotation performed in supine decubitus (50% for TFL, 76.7% for S).

DISCUSSION

The study hypothesis was not confirmed, since hip joint positioning and the learning curve on an MVC test did not affect EMG signal during MVC of GMax, GMed, TFL and S muscles. Therefore, a single session and one specific test is enough to assess MVC in hip abductors (abduction in lateral decubitus) and flexors (hip flexion/abduction/lateral rotation in supine position). This method could be applied to assess muscle function after THA, and particularly to compare different approaches.

LEVEL OF EVIDENCE

III, case-matched study.

Lower Limb Joint Angular Position and Muscle Activity During Elliptical Exercise in Healthy Young Men

The purpose of this study was to compare lower extremity joint angular position and muscle activity during elliptical exercise using different foot positions and also during exercise on a lateral elliptical trainer. Sixteen men exercised on a lateral elliptical and on a standard elliptical trainer using straight foot position, increased toe-out angle, and a wide step. Motion capture and electromyography systems were used to obtain 3D lower extremity joint kinematics and muscle activity, respectively. The lateral trainer produced greater sagittal and frontal plane knee range of motion (ROM), greater peak knee flexion and extension, and higher vastus medialis activation compared with other conditions (P < .05). Toe-out and wide step produced the greatest and smallest peak knee adduction angles, respectively (P < .05). The lateral trainer produced greater sagittal and frontal plane hip ROM and greater peak hip extension and flexion compared with all other conditions (P < .05). Toe-out angle produced the largest peak hip external rotation angle and lowest gluteus muscle activation (P < .05). Findings from this study indicate that standard elliptical exercise with wide step may place the knee joint in a desirable frontal plane angular position to reduce medial knee loads, and that lateral elliptical exercise could help improve quadriceps strength but could also lead to larger knee contact forces.

A narrative review of manual muscle testing and implications for muscle testing research

OBJECTIVE

Manual muscle testing (MMT) is used for a variety of purposes in health care by medical, osteopathic, chiropractic, physical therapy, rehabilitation, and athletic training professionals. The purpose of this study is to provide a narrative review of variations in techniques, durations, and forces used in MMT putting applied kinesiology (AK) muscle testing in context and highlighting aspects of muscle testing important to report in MMT research.

METHOD

PubMed, the Collected Papers of the International College of Applied Kinesiology-USA, and related texts were searched on the subjects of MMT, maximum voluntary isometric contraction testing, and make/break testing. Force parameters (magnitude, duration, timing of application), testing variations of MMT, and normative data were collected and evaluated.

RESULTS

"Break" tests aim to evaluate the muscle's ability to resist a gradually increasing pressure and may test different aspects of neuromuscular control than tests against fixed resistances. Applied kinesiologists use submaximal manual break tests and a binary grading scale to test short-term changes in muscle function in response to challenges. Many of the studies reviewed were not consistent in reporting parameters for testing.

CONCLUSIONS

To increase the chances for replication, studies using MMT should specify parameters of the tests used, such as exact procedures and instrumentation, duration of test, peak force, and timing of application of force.

Muscle torque in total knee arthroplasty: comparison of subvastus and midvastus approaches

The subvastus and midvastus approaches are two of the most commonly performed quadriceps preserving approaches for total knee arthroplasty (TKA), which can hasten functional recovery and rehabilitation. However, there has not been sufficient investigation with respect to a quantitative comparison between the two approaches in terms of muscle strength. To compare outcomes with respect to muscle strength between these two approaches, quadriceps and hamstring muscle torques of 20 patients who underwent primary TKA with the subvastus (SV) approach and 10 patients who received the midvastus (MV) approach were measured after surgery. The median age of patients in the SV group (68 years, range 53-77 years) was significantly different that the median age of patients in the MV group (61 years, range 50-73 years) (P = 0.0141). There was no significant difference in patient weight, height, or postoperative duration before muscle testing between the SV and MV groups. There were no significant differences in peak muscle torque or hamstring/quadriceps (H/Q) ratio between the groups. We thus conclude peak muscle torque and H/Q ratios were not statistically different with the SV or MV approach, therefore functional outcome is comparable.