Correcting movement syndromes: the role of training load and its effects on muscle activity

Mehls, Kelton; Grubbs, Brandon; Stevens, Sandra L.; Martinez, Sarah C.; Jin, Ying; Coons, John M.

doi:10.1007/s11332-021-00764-5

Cited by 3 publications

(5 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, it is unclear if technique remains consistent across the entire spectrum of these loads when training to, or near voluntary failure. Earlier research supports the assumption that technical variations depend on load, as evidenced by the influence of load on EMG signals ( Mehls et al, 2021 ; Martinez, Coons & Mehls, 2023 ). Repetition range might influence joint and barbell kinematics and EMG amplitude during different phases of the lift due to compensatory strategies, which are indirect measures ( Morton et al, 2019 ; Larsen, Haugen & van den Tillaar, 2022 ) of understanding differences between a given repetition range and 1RM squat strength.…”

Section: Introductionsupporting

confidence: 56%

Comparison of kinematics and electromyography in the last repetition during different maximum repetition sets in the barbell back squat

Falch,

Hegdahl Gundersen,

Larsen

et al. 2024

PeerJ

View full text Add to dashboard Cite

Background The barbell squat is an exercise used to strengthen the lower limbs, with implications for both performance in sports and improving movement during everyday tasks. Although the exercise is being trained across a variety of repetition ranges, the technical requirements may vary, affecting appropriate repetition range for specific training goals. Methods A randomised within-subject design was used to compare kinematics and surface electromyography (EMG) in the lower extremities during different concentric phases (pre-, sticking- and post-sticking region) of the last repetition when performing squats at different repetition maximums (RMs). Thirteen strength-trained men (age: 23.6 ± 1.9 years; height: 181.1 ± 6.5 cm; body mass: 82.2 kg, 1RM: 122.8 ± 16.2, relative strength: 1.5 ± 0.2 x body mass in external load) performed a 1, 3, 6, and 10RM squat, in a randomised order. Results The main findings were that barbell-, ankle-, knee- and hip kinematics were similar across different repetition ranges, except for a smaller trunk lean at 1RM in the pre-sticking region compared to other repetitions and in the sticking region compared to 10RM (p ≤ 0.04). Furthermore, 1RM revealed significantly higher EMG amplitude in the vastus lateralis, gastrocnemius and soleus in the sticking and post-sticking regions when compared to 10RM. It was concluded that 10RM may locally fatigue the vastus lateralis and plantar flexors, explaining the lower EMG amplitude. The observed differences indicate that requirements vary for completing the final repetition of the 10RM compared to the 1RM, an important aspect to consider in training to enhance 1RM strength.

show abstract

Section: Introductionsupporting

confidence: 56%

Comparison of kinematics and electromyography in the last repetition during different maximum repetition sets in the barbell back squat

Falch,

Hegdahl Gundersen,

Larsen

et al. 2024

PeerJ

View full text Add to dashboard Cite

show abstract

“…The descending phase of the back squat was recorded from the beginning of the downward movement until the buttocks touched the bungee cord, while the ascending phase was recorded from the touching of the cord until the participant returned to a fully erect position. A metronome was used to control speed of the movement with two second descending and one second ascending phases (Mehls et al, 2021).…”

Section: Methodsmentioning

confidence: 99%

“…Due these kinematic differences, females tend to display greater internal hip rotation and knee adduction compared to male counterparts during hip extension (Buchman‐Pearle, Kingston, & Acker, 2021; Flaxman, Smith, & Benoit, 2014). Additionally, several studies have noted sex differences for muscle activity patterns during the back squat and isokinetic movements (Krishnan & Williams, 2009; Mehls et al, 2021), yet literature lacks communication regarding the effect of load on muscle activity in females.…”

Section: Introductionmentioning

confidence: 99%

Effect of external load on muscle activation during the barbell back squat

Martinez

Coons

Mehls

2022

European Journal of Sport Science

View full text Add to dashboard Cite

The aim of this study was to compare gluteus maximus-to-hamstring (GM:H) co-activation, hamstrings-to-quadriceps (H:Q) co-activation, and mean muscle activity in the vastus lateralis (VL), vastus medialis (VM), rectus femoris (RM), gluteus maximus (GM), semitendinosus (ST), and bicep femoris (BF) muscles across a range of training loads (40%, 50%, 50%, 70%, 80% 90% 1RM) of the barbell back squat in resistance trained females. Surface electromyography (EMG) was observed in 18 healthy resistance trained females for the VL, VM, RM, GM, ST, and BF during the ascending and descending phase of the back squat. During the ascending phase, the VL, VM, RM, GM, ST, and BF displayed significantly more EMG activation at 90% 1RM compared to 40%-70% (p < .03). During the descending phase, there were no significant differences displayed in mean muscle activity at 40%-80% of 1RM compared to 90% of 1RM. There were no significant differences in H-Q co-activation and GM-H co-activation during the ascending or descending phase across external loads. These findings are similar to the results found in similar studies using male participants and support that higher training intensities (80%-90% 1RM) of the barbell back squat significantly activate muscles surrounding the hip compared to lower loads (40%-70%). The results of this study also suggest that training intensities of 80% 1RM and 90% 1RM elicits the similar musculature activation in the muscle surrounding the hip in resistance trained females. Highlights. During the back squat, mean muscle activity of the hip and leg muscles increased linearly with exercise intensity (40%-90% of one-repetition max) in resistance trained females. . No significant difference in mean activity were noted between 80% and 90% of one-repetition max during the ascending and descending phases. . During the ascending phase, 80% of one-repetition max generated the highest gluteus maximus to hamstring activity co-activation ratio. . During the descending phase, 40% of one-repetition max produced a gluteus maximus to hamstring activity co-activation ratio closest to 1.0.

show abstract

“…It is well documented that increases in sEMG amplitudes are dependent on numerous variables including increases in muscle fiber recruitment, motor unit firing frequency, or peripheral factors (28,45,46). While muscle activity does increase with external load, it does not occur in a linear fashion as it is muscle and load (percentage of 1-RM) dependent (34,44). This hypothesis can be further observed if BHT and BGB 5-RM are converted into 1-RM (5-RM load divided by 87%) (26), then the recorded 5-RM loads of each exercise (BHT, BGB, BBHT, BBGB) are compared within each of their respected groups as a percentage of load to the non-banded 1-RM (5-RM BHT and 5-RM BBHT compared to estimated 1-RM BHT; 5-RM BGB and 5-RM BBGB compared to estimated 1-RM BGB).…”

Section: Discussionmentioning

confidence: 99%

“…When reciprocal inhibition is presented, neuromuscular dysfunction is hypothesized to occur triggering a movement syndrome, often associated with muscular imbalances, leading to alterations of neuromuscular activity surrounding a joint. Those alterations in neuromuscular activity may result in synergistic muscles becoming overactive to compensate for weak or inhibited prime movers (i.e., synergistic dominance) (7)(8)(9)34,35).…”

Section: Discussionmentioning

confidence: 99%

Effects of Band-Resisted Abduction on Muscle Activity between the Barbell Hip Thrust and Barbell Glute Bridge

Kennedy,

Casebolt,

Farren

et al. 2023

Int'l Journal of Strength & Conditioning

View full text Add to dashboard Cite

The importance of hip extensor and abductor muscles for sport performance and injury reduction is well-documented. To target these muscle groups, the barbell hip thrust and barbell glute bridge are used to load the posterior kinetic chain while band-resisted abduction exercises, like band-resisted side stepping, target the lateral kinetic chain. However, combining band-resisted hip abduction with barbell hip-extension dominant exercises has not yet been investigated. In this study, ten male subjects underwent a two-part research protocol with surface electromyography (sEMG) measured during a 5-repetition maximum (5-RM) load performance to determine differences in peak and mean muscular activity between band-resisted barbell hip thrust (BBHT) and barbell hip thrust (BHT), and between band-resisted barbell glute bridge (BBGB) and barbell glute bridge (BGB). The results indicated three significant differences between the pairs, with both banded conditions eliciting greater sEMG activity in the Upper Gluteus Maximus compared to non-banded conditions. However, BGB unexpectedly elicited greater sEMG activity in the Gluteus Medius compared to BBGB. The differences in muscle activity could potentially be explained by reciprocal inhibition and synergistic dominance. Further research is needed to make definitive statements on the superiority of band-resisted barbell exercises over non-banded barbell exercises and transferability to sport performance.

show abstract

Correcting movement syndromes: the role of training load and its effects on muscle activity

Cited by 3 publications

References 34 publications

Comparison of kinematics and electromyography in the last repetition during different maximum repetition sets in the barbell back squat

Comparison of kinematics and electromyography in the last repetition during different maximum repetition sets in the barbell back squat

Effect of external load on muscle activation during the barbell back squat

Effects of Band-Resisted Abduction on Muscle Activity between the Barbell Hip Thrust and Barbell Glute Bridge

Contact Info

Product

Resources

About