Single Leg Squat Exercise Research Articles

Muscular Activation Levels of Subjects with Low Medial Longitudinal Arch During Single-Leg Squat and Single-Leg Balancing Exercises on Surfaces of Different Hardness

Background: The primary aim of this study is to examine the effect of the stiffness of rehabilitation material on muscle activation in individuals with low medial longitudinal arch. The secondary aim is to compare the effects of single-leg balancing and single-leg squat exercises on the activation of the muscles around the ankle in the same individuals. Methods: Twelve individuals with low medial longitudinal arch and 18 healthy control participants were included. Participants were asked to perform the single-leg balance and single-leg squat exercises on Theraband stability trainers of three different stiffness levels. Activation of the peroneus longus, peroneus brevis, tibialis anterior, medial and lateral gastrocnemius muscles during exercises was evaluated by surface electromyography. Results: The single-leg balancing exercise performed on soft and very soft ground was more effective than single-leg squat in increasing the activation of the lateral gastrocnemius muscle in participants with a low medial longitudinal arch. It was determined that performing single-leg squat exercise on a very soft surface instead of hard ground caused more muscular activation in the peroneus brevis, tibialis anterior, and medial gastrocnemius in the same individuals. Conclusions: The exercise progression to be applied on different surfaces to increase the activation of the muscles around the ankle in individuals with a low medial longitudinal arch and in healthy individuals without a low medial longitudinal arch was different.

Effects of a newly developed toe exercise program combined with the intrinsic and extrinsic muscle trainings on toe function: a case series.

Foot and toe function is important for not only sports performance but also preventing and treating musculoskeletal disorders. Although strengthening training specific to intrinsic and extrinsic muscles has been recommended, insufficient information is available in toe exercises in their variation and evidences compared to shoulder or lumbopelvic training strategies. The aim was to examine the effects of a newly developed foot muscle exercise program on toe function in individuals during the growth period. This is a single-group, pretest-posttest case series. Both feet of seven male patients in their growth period with sports-related overuse injuries of the lower extremities (mean age, 11 years) underwent a four-week strength exercise of the toes, consisting of intrinsic and extrinsic muscle-targeted exercises. Main outcome measures were as follows: 1) flexion force of each toe; 2) compression force of each toe; 3) dexterity of the toes evaluated using the "rock-paper-scissors test"; 4) toe loading during single-leg squat exercise. An F-scan system was used to measure 2 and 4. All patients performed the program appropriately and completed the program for four weeks. Significant improvements were observed in the outcome measures of 1 to 4. The combined exercise program for the intrinsic and extrinsic muscles of the foot effectively improved toe strength, dexterity, and loading during dynamic motion and could be easily performed in individuals during the growth period.

The Validity and Reliability of a Real-Time Biofeedback System for Lumbopelvic Control Training in Baseball Players.

This study validates real-time biofeedback for lumbopelvic control training in baseball. The lumbopelvic region is crucial for generating kinetic energy in pitching. Real-time biofeedback enhances training effectiveness and reduces injury risk. The validity and reliability of this system were examined. This study was to investigate the validity and reliability of the real-time biofeedback system for lumbopelvic control training. Twelve baseball players participated in this study, with data collected in two sessions separated by a week. All participants needed to do the lateral slide exercise and single-leg squat exercise in each session. Pelvic angles detected by the real-time biofeedback system were compared to the three-dimensional motion capture system (VICON) during training sessions. Additionally, pelvic angles measured by the biofeedback system were compared between the two training sessions. The real-time biofeedback system exhibited moderate to strong correlations with VICON in both exercises: lateral slide exercise (r = 0.66-0.88, p < 0.05) and single-leg squat exercise (r = 0.70-0.85, p < 0.05). Good to excellent reliability was observed between the first and second sessions for both exercises: lateral slide exercise (ICC = 0.76-0.97) and single-leg squat exercise (ICC = 0.79-0.90). The real-time biofeedback system for lumbopelvic control training, accurately providing the correct pelvic angle during training, could enhance training effectiveness.

McConnell patelar taping improves unipodal squat postural control in women with patellofemoral pain syndrome: A randomised trial

McConnell's patellar taping is indicated for the treatment of women with Patellofemoral Pain Syndrome, however the literature points to controversial evidence, and does not establish the effect on postural control. This is a randomized trial study that aimed to compare the effect of McConnell taping (MT) with a Placebo taping (PT), during functional tasks that assess dynamic postural control, such as squatting and ascending/descending stairs, using a force platform among women with patellofemoral pain syndrome (PFPS). The participants were randomly assigned to two treatment groups: MT (n = 15) and PT (n = 15). The primary outcome was dynamic postural control in the unipodal squatting test and the test of ascending and descending steps evaluated using a force platform, before and after the application of the intervention. The results showed that in the single leg squat exercise, the MT group performed better compared to the PT group in the center of pressure oscillation area (A-COP), and anteroposterior and mediolateral velocity. For ascending stairs, the PT group performed better in the A-COP compared to the MT group. The stair descent showed no differences between the groups or moments of assessment. So, MT can be used to improve postural control in single-legged squat exercises.

Lower limb muscle performance during a closed chain single leg squat and a squat jump in people with leg weakness after stroke: A comparative study

Abstract Objective: To determine if the intention to perform an exercise at speed leads to beneficial alterations in kinematic and kinetic components of the movement in people with post-stroke hemiplegia. Design: Comparative study. Setting: Subacute metropolitan rehabilitation hospital. Participants: Convenience sample of patients admitted as an inpatient or outpatient with a diagnosis of stroke with lower limb weakness, functional ambulation category score ≥3, and ability to walk ≥14metres. Methods: Participants performed a single leg squat exercise on their paretic and nonparetic legs on a leg sled under three conditions: 1) self-selected speed (SS), 2) fast speed (FS), 3) jump squat (JS). Measures of displacement, flight time, peak concentric velocity, and muscle excitation (via electromyography) were compared between legs and conditions. Results: Eleven participants (age: 56 ± 17 years; median time since stroke onset: 3.3 [IQR 3,41] months) were tested. All participants achieved a jump during the JS, as measured by displacement and flight time respectively, on both their paretic (0.25 ± 0.16 m and 0.42 ± 0.18 s) and nonparetic (0.49 ± 0.36 m and 0.73 ± 0.28 s) legs; however it was significantly lower on the non-paretic leg (p &lt; 0.05). Peak concentric velocity increased concordantly with intended movement speed (JS-FS paretic: 0.96 m/s, non-paretic: 0.54 m/s; FS-SS paretic 0.69 m/s, nonparetic 0.38 m/s; JS-SS paretic 1.66 m/s, non-paretic 0.92 m/s). Similarly, muscle excitation increased significantly (p &lt; 0.05) with faster speed for the paretic and nonparetic vastus lateralis. For gastrocnemius, the only significant difference was an increase during nonparetic JS vs. SS and FS. Conclusions: Speed affects the kinematic and kinetic components of the movement. Performing exercises ballistically may improve training outcomes for people post-stroke.

Lower limb muscle performance during a closed chain single leg squat and a squat jump in people with leg weakness after stroke: A comparative study

Objective: To determine if the intention to perform an exercise at speed leads to beneficial alterations in kinematic and kinetic components of the movement in people with post-stroke hemiplegia. Design: Comparative study. Setting: Subacute metropolitan rehabilitation hospital. Participants: Convenience sample of patients admitted as an inpatient or outpatient with a diagnosis of stroke with lower limb weakness, functional ambulation category score ≥3, and ability to walk ≥14metres. Methods: Participants performed a single leg squat exercise on their paretic and nonparetic legs on a leg sled under three conditions: 1) self-selected speed (SS), 2) fast speed (FS), 3) jump squat (JS). Measures of displacement, flight time, peak concentric velocity, and muscle excitation (via electromyography) were compared between legs and conditions. Results: Eleven participants (age: 56 ± 17 years; median time since stroke onset: 3.3 [IQR 3,41] months) were tested. All participants achieved a jump during the JS, as measured by displacement and flight time respectively, on both their paretic (0.25 ± 0.16 m and 0.42 ± 0.18 s) and nonparetic (0.49 ± 0.36 m and 0.73 ± 0.28 s) legs; however it was significantly lower on the non-paretic leg (p &lt; 0.05). Peak concentric velocity increased concordantly with intended movement speed (JS-FS paretic: 0.96 m/s, non-paretic: 0.54 m/s; FS-SS paretic 0.69 m/s, nonparetic 0.38 m/s; JS-SS paretic 1.66 m/s, non-paretic 0.92 m/s). Similarly, muscle excitation increased significantly (p &lt; 0.05) with faster speed for the paretic and nonparetic vastus lateralis. For gastrocnemius, the only significant difference was an increase during nonparetic JS vs. SS and FS. Conclusions: Speed affects the kinematic and kinetic components of the movement. Performing exercises ballistically may improve training outcomes for people post-stroke.

Lower limb muscle performance during a closed chain single leg squat and a squat jump in people with leg weakness after stroke: A comparative study

Objective: To determine if the intention to perform an exercise at speed leads to beneficial alterations in kinematic and kinetic components of the movement in people with post-stroke hemiplegia. Design: Comparative study. Setting: Subacute metropolitan rehabilitation hospital. Participants: Convenience sample of patients admitted as an inpatient or outpatient with a diagnosis of stroke with lower limb weakness, functional ambulation category score ≥3, and ability to walk ≥14metres. Methods: Participants performed a single leg squat exercise on their paretic and nonparetic legs on a leg sled under three conditions: 1) self-selected speed (SS), 2) fast speed (FS), 3) jump squat (JS). Measures of displacement, flight time, peak concentric velocity, and muscle excitation (via electromyography) were compared between legs and conditions. Results: Eleven participants (age: 56 ± 17 years; median time since stroke onset: 3.3 [IQR 3,41] months) were tested. All participants achieved a jump during the JS, as measured by displacement and flight time respectively, on both their paretic (0.25 ± 0.16 m and 0.42 ± 0.18 s) and nonparetic (0.49 ± 0.36 m and 0.73 ± 0.28 s) legs; however it was significantly lower on the non-paretic leg (p &lt; 0.05). Peak concentric velocity increased concordantly with intended movement speed (JS-FS paretic: 0.96 m/s, non-paretic: 0.54 m/s; FS-SS paretic 0.69 m/s, nonparetic 0.38 m/s; JS-SS paretic 1.66 m/s, non-paretic 0.92 m/s). Similarly, muscle excitation increased significantly (p &lt; 0.05) with faster speed for the paretic and nonparetic vastus lateralis. For gastrocnemius, the only significant difference was an increase during nonparetic JS vs. SS and FS. Conclusions: Speed affects the kinematic and kinetic components of the movement. Performing exercises ballistically may improve training outcomes for people post-stroke.

Intermuscular Motor Unit recruitment of Lower limb according to contralateral hip motion during dynamic and isometric single leg squat

Background/Objectives: The purpose of this study is to compare the change in intermuscular motor unit recruitment of lower limb and finding better exercises. Methods/Statistical analysis: Twenty-eight male and female adults agreed to participate in this study. Volunteers performed six motion in random sequence what used program of draw. One way repeated ANOVA was used to compare the change. A post hoc test was performed using Bonferroni correction. Findings: There was a significant difference that was about intermuscular motor unit recruitment of lower limb between isometric and dynamic. When subjects took single leg squat (SLS) exercise during hip flexion, abduction and extension with knee flexion of non-dominant lower limb by isometric and dynamic, only one muscle, vastus medilalis was a significant difference in isometric. Improvements/Applications: the isometric SLS exercise was more effective of lower limb. Also, doing SLS exercise, extension and abduction were more effective of lower limb.

Relative muscle contribution of lower extremity muscles during isokinetic single leg squat in patients following reconstruction of the anterior cruciate ligament

BACKGROUND: The single-leg squat (SLS) is a common strengthening exercise after anterior cruciate ligament reconstruction (ACLR) surgery. The multi-joint nature of squatting may allow patients to shift the demand from the target muscle group to its synergies, thus reducing the strengthening effect of the SLS exercise. OBJECTIVE: To compare the muscular contribution in the involved and uninvolved side of the ACLR patients and both sides of the ACLR patients with the matched control group during SLS exercise. METHOD: Seventeen athletic men with unilateral ACL reconstruction and 16 athletic healthy men participated. Integrated Electromyography was used to calculate the relative contributions of, Vastus Medialis (VM), Vastus Lateralis (VL), rectus femoris (RF), Gluteus maximus (GMax) and Soleus (SOL) muscles to SLS performance and squat peak force was measured with a Biodex System 3 isokinetic dynamometer. RESULTS: The VM muscle contribution was significantly lower and the VL and GMax contribution was higher on the involved side of the ACLR patients compared to their uninvolved side and the control group. The SLS peak force was significantly lower on the involved side compared to the uninvolved side. CONCLUSION: The increased VL and GMax muscle contribution might be a compensatory mechanism for the reduced VM contribution on the involved side.

The biomechanical challenge of single leg squat exercise and implications for exercise progression

The biomechanical challenge of single leg squat exercise and implications for exercise progression

Movement Accuracy Changes Muscle-Activation Strategies in Female Subjects During a Novel Single-Leg Weight-Bearing Task

Understanding of how female subjects learn to move accurately during a resisted weight-bearing task is limited. The purpose of this study was to examine the muscle activation patterns used by female subjects in learning a novel single-leg squat (SLS) task under visual and nonvisual conditions. Prospective training study. University research setting. Ten healthy young female participants. Subjects tracked a sinusoidal target (knee displacement) during a resisted SLS exercise during the course of 4 days, under eyes open (EO) and eyes closed (EC) conditions with the use of a custom-designed weight-bearing exercise device. The accuracy of performance in tracking the target and electromyographic activity (EMG) of 5 muscles around the knee were monitored. Subjects improved their accuracy of performance by day 2 (40% decrease in error) and retained the accuracy on day 4. Error during the EC condition was 3 times greater than EO condition. Quadriceps-to-hamstrings coactivation ratio increased with the improved accuracy from the learning. Absence of visual feedback was accompanied by a decrease in the quadriceps-to-hamstrings coactivation ratio for this task. The muscle synergistic activity around the knee changes as the accuracy of the task improves during a resisted weight-bearing task. This activation pattern represents a feed forward control plan that the central nervous system adopted to optimize accurate weight-bearing knee displacement. Rehabilitation specialists should consider manipulating the visual feedback and accuracy of performance when developing weight-bearing rehabilitation training protocols to improve neuromuscular control in female patients.

Weight-Bearing Exercise Accuracy Influences Muscle Activation Strategies of the Knee

Dynamic stability of the knee joint is a research topicof increasing focus after ACL injury, stroke, and incomplete spinal cord injury. Since rehabilitation programs use functional weightbearing tasks to improve neuromuscular control of the knee, it is important to understand the adaptability of muscle control strategies during weight-bearing exercise. The purpose of this study was to compare muscle activation patterns during a single leg squat (SLS) exercise performed before and after feedback-controlled training. This was a cross-sectional comparative study. Fifteen young, healthy individuals performed the SLS exercise while tracking a sinusoidal target with flexion and extension of the knee. The SLS instrument provided bidirectional resistance that was normalized to body weight. Six trials of 10 repetitions of the SLSs were performed to quantify improved performance (learning). Electromyographic activity from five muscles that cross the knee was analyzed. Accuracy of performance was measured by calculating the error between the target and actual knee displacement. Reduction in error measurements verified that individuals increased the accuracy of performance in each trial and retained this improvement across trials (p < 0.05). Modulation in muscle activity as a result of learning was reflected mainly in the biceps femoris, rectus femoris, and vastus lateralis muscles. Increased accuracy with the SLS exercise was accompanied by a decrease in coactivation of selected musculature around the knee. This study presents a novel approach to quantify the effect of performance on muscle synergistic activation patterns during weight-bearing exercise. Controlled strengthening, as defined in this study, emphasizes accuracy of performance in conjunction with principles of strength training and has implications to knee control.

INFLUENCE OF AGE ON NEUROMUSCULAR CONTROL OF THE KNEE.

Purpose/Hypothesis: An increased incidence of injury has made neuro-muscular control of the knee joint a focus of attention in motor control research. The central nervous system (CNS) controls the knee against unpredictable perturbations that occur during movement. Age associated changes in the musculoskeletal, neuromuscular and sensory systems compromise the ability of the elderly to respond effectively to a perturbation, thereby placing the older population at a higher risk of injury. Weight bearing exercises have been primarily used to re-educate neuromuscular control of the knee following pathology. Limited information is available on the strategies used by the elderly to control the knee during dynamic activities. This study examined the effect of age on the neuromuscular control of the knee by examining accuracy of performance, muscle synergies and long latency reflexes (LLR) during a functional weight bearing exercise. We hypothesized that the elderly would show greater impairment in neuro-muscular control than the young. Number of Subjects: Ten young and ten elderly subjects performed a single leg squat exercise (SLS) while tracking a sinusoidal target with knee motion at different levels of resistances (4%, 8% and 12% body weight). Materials/Methods: Subjects first performed a set of learning trials to gain proficiency with the task. Later, they performed the SLSs with random perturbations (drop in resistance level to 0% BW) during the knee flexion phase. A split plot repeated measures ANOVA was used to assess between and within group differences in movement accuracy, synergistic activation patterns (EMG), and long latency reflexes. Results: The elderly group 1) had a 50% greater absolute error in tracking the target angle when compared to the younger group (p < 0.05); 2) showed a 60% greater activation of the quadriceps and hamstrings at all levels of resistances as compared to the younger group (p < 0.05); and showed 15% greater LLR for the quadriceps and biceps femoris when compared to the younger group (p < 0.05). Conclusions: These results indicate that the elderly recruit higher percentages of MVC and have greater error when performing the SLS weight bearing exercise. Clinical Relevance: Age associated changes of the sensorimotor system necessitates greater muscle activity to help stabilize the knee in the elderly. These findings provide important clinical implications when developing rehabilitation programs for the young and elderly.