scholarly journals Muscle Activation During Landing Before and After Fatigue in Individuals With or Without Chronic Ankle Instability

2016 ◽  
Vol 51 (8) ◽  
pp. 629-636 ◽  
Author(s):  
Kathryn A. Webster ◽  
Brian G. Pietrosimone ◽  
Phillip A. Gribble

Context: Ankle instability is a common condition in physically active individuals. It often occurs during a jump landing or lateral motion, particularly when participants are fatigued. Objective: To compare muscle activation during a lateral hop prefatigue and postfatigue in individuals with or without chronic ankle instability (CAI). Design: Cross-sectional study. Setting: Sports medicine research laboratory. Patients or Other Participants: A total of 32 physically active participants volunteered for the study. Sixteen participants with CAI (8 men, 8 women; age = 20.50 ± 2.00 years, height = 172.25 ± 10.87 cm, mass = 69.13 ± 13.31 kg) were matched with 16 control participants without CAI (8 men, 8 women; age = 22.00 ± 3.30 years, height = 170.50 ± 9.94 cm, mass = 69.63 ± 14.82 kg) by age, height, mass, sex, and affected side. Intervention(s): Electromyography of the tibialis anterior, peroneus longus, gluteus medius, and gluteus maximus was measured before and after a functional fatigue protocol. Main Outcome Measure(s): Activation of 4 lower extremity muscles was measured 200 milliseconds before and after landing from a lateral hop. Results: We observed no interactions. The group main effects for the peroneus longus demonstrated higher muscle activation in the CAI group (52.89% ± 11.36%) than in the control group (41.12% ± 11.36%) just before landing the lateral hop (F1,30 = 8.58, P = .01), with a strong effect size (d = 1.01). The gluteus maximus also demonstrated higher muscle activation in the CAI group (45.55% ± 12.08%) than in the control group (36.81% ± 12.08%) just before landing the lateral hop (F1,30 = 4.19, P = .049), with a moderate effect size (d = 0.71). We observed a main effect for fatigue for the tibialis anterior, with postfatigue activation higher than prefatigue activation (F1,30 = 7.45, P = .01). No differences were present between groups for the gluteus medius. Conclusions: Our results support the presence of a centralized feed-forward neuromuscular alteration in patients with CAI, not only in the ankle-joint muscles but also in the proximal hip muscles. These results may have implications for rehabilitation programs in these patients.

2020 ◽  
Vol 55 (1) ◽  
pp. 49-57 ◽  
Author(s):  
Alexandra F. DeJong ◽  
L. Colby Mangum ◽  
Jay Hertel

Context Impairments in dynamic postural control and gluteal muscle activation have been associated with the development of symptoms related to long-term injury, which are characteristic of chronic ankle instability (CAI). Ultrasound imaging (USI) provides a visual means to explore muscle thickness throughout movement; however, USI functional-activation ratios (FARs) of the gluteal muscles during dynamic balance exercises have not been investigated. Objective To determine differences in gluteus maximus and gluteus medius FARs using USI, Y-Balance Test (YBT) performance, and lower extremity kinematics in individuals with or without CAI. Design Cross-sectional study. Setting University laboratory. Patients or Other Participants Twenty adults with CAI (10 men, 10 women; age = 21.70 ± 2.32 years, height = 172.74 ± 11.28 cm, mass = 74.26 ± 15.24 kg) and 20 adults without CAI (10 men, 10 women; age = 21.20 ± 2.79 years, height = 173.18 ± 15.16 cm, mass = 70.89 ± 12.18 kg). Intervention(s) Unilateral static ultrasound images of the gluteal muscles during quiet stance and to the point of maximum YBT reach directions were obtained over 3 trials. Hip, knee, and ankle sagittal-plane kinematics were collected with motion-capture software. Main Outcome Measure(s) Gluteal thickness was normalized to quiet stance to yield FARs for each muscle in each YBT direction. We averaged normalized reach distances and obtained average peak kinematics. Independent t tests, mean differences, and Cohen d effect sizes were calculated to determine group differences for all outcome measures. Results The CAI group had anterior-reach deficits compared with the control group (mean difference = 4.37%, Cohen d = 0.77, P = .02). The CAI group demonstrated greater anterior gluteus maximus FARs than the control group (mean difference = 0.08, Cohen d = 0.57, P = .05). Conclusions The CAI group demonstrated YBT reach deficits and alterations in proximal muscle activation. Increased reliance on the gluteus maximus during dynamic conditions may contribute to distal joint dysfunction in this population.


2015 ◽  
Vol 50 (4) ◽  
pp. 350-357 ◽  
Author(s):  
Mark A. Feger ◽  
Luke Donovan ◽  
Joseph M. Hart ◽  
Jay Hertel

Context Ankle sprains are among the most common musculoskeletal injuries, and many individuals with ankle sprains develop chronic ankle instability (CAI). Individuals with CAI exhibit proprioceptive and postural-control deficits, as well as altered osteokinematics, during gait. Neuromuscular activity is theorized to play a pivotal role in CAI, but deficits during walking are unclear. Objective To compare motor-recruitment patterns as demonstrated by surface electromyography amplitudes between participants with CAI and healthy control participants during walking. Design Descriptive laboratory study. Setting Laboratory. Patients or Other Participants Fifteen adults with CAI (5 men, 10 women; age = 23 ± 4.2 years, height = 173 ± 10.8 cm, mass = 72.4 ± 14 kg) and 15 matched healthy control adults (5 men, 10 women; age = 22.9 ± 3.4 years, height = 173 ± 9.4 cm, mass = 70.8 ± 18 kg). Intervention(s) Participants walked shod on a treadmill while surface electromyography signals were recorded from the anterior tibialis, peroneus longus, lateral gastrocnemius, rectus femoris, biceps femoris, and gluteus medius muscles. Main Outcome Measure(s) Preinitial contact amplitude, postinitial contact amplitude, time of activation relative to initial contact, and percentage of activation time across the stride cycle were calculated for each muscle. Results Time of activation for all muscles tested occurred earlier in the CAI group than in the control group. The peroneus longus was activated for a longer duration across the entire stride cycle in the CAI group (36.0% ± 10.3%) than the control group (23.3% ± 22.2%; P = .05). No differences were noted between groups for measures of electromyographic amplitude at either preinitial or postinitial contact (P > .05). Conclusions We identified differences between the CAI and control groups in the timing of muscle activation relative to heel strike in multiple lower extremity muscles and in the percentage of activation time across the entire stride cycle in the peroneus longus muscle. Individuals with CAI demonstrated neuromuscular-activation strategies throughout the lower extremity that were different from those of healthy control participants. Targeted therapeutic interventions for CAI may need to be focused on restoring normal neuromuscular function during gait.


Author(s):  
Seung-Min Baik ◽  
Heon-Seock Cynn ◽  
Chung-Hwi Yi ◽  
Ji-Hyun Lee ◽  
Jung-Hoon Choi ◽  
...  

BACKGROUND: The effectiveness of side-sling plank (SSP) exercises on trunk and hip muscle activation in subjects with gluteus medius (Gmed) weakness is unclear. OBJECTIVE: To quantify muscle activation of the rectus abdominis (RA), external oblique (EO), erector spinae (ES), lumbar multifidus (LM), Gmed, gluteus maximus (Gmax), and tensor fasciae latae (TFL) during SSP with three different hip rotations compared to side-lying hip abduction (SHA) exercise in subjects with Gmed weakness. METHODS: Twenty-two subjects with Gmed weakness were recruited. SHA and three types of SSP exercises were performed: SSP with neutral hip (SSP-N), hip lateral rotation (SSP-L), and hip medial rotation (SSP-M). Surface electromyography was used to measure the activation of the trunk and hip muscles. RESULTS: The trunk and hip muscles activations were generally significantly higher level during three SSP than SHA. SSP-M showed significantly lower EO activation while significantly higher ES and LM activation than SSP-L. Gmed activation was significantly higher during SSP-M than during SSP-L. TFL activation was significantly lower during SSP-M than during SSP-N and SSP-L. CONCLUSIONS: SSP could be prescribed for patients who have reduced Gmed strength after injuries. Especially, SSP-M could be applied for patients who have Gmed weakness with dominant TFL.


Author(s):  
Kristina Zaičenkovienė ◽  
Renata Rakovaitė

Research background. Falling is one of the most important problems in the elderly’s mobility disorder, which is most often affected by the loss of balance. It is known that Pilates exercises could help to increase the deep muscle strength, improve posture and proprioception, which affects the improvement of the balance. Objective – to evaluate the effects of Pilates exercises on the elderly’s static and dynamic balance. Methodology. The study population consisted of 20 volunteers, men and women, who were divided into Pilates exercises (n = 10, age 65.1 ± 2.6) and control (n = 10, age 68.6 ± 4.9) groups. The study group participated in Pilates classes 2 times per week for six weeks (session duration 60 minutes). The control group did not participate in any physical activity, but they were physically active as usually in their daily life. The main outcome measures were assessed before and after the intervention. The static balance was assessed by measuring posturographic parameters using the force platform, dynamic balance was measured with the Timed up and Go Test (TUG) and the Four Square Step Test (FSST). Results. The results showed signifcant improvement in static balance of the experimental group after the Pilates exercises during standing tests when the feet were apart, eyes opened and closed and when the feet together with eyes opened, and when the foot was in front of the other foot. The results of the control group did not differ during both tests. The results of both groups did not differ in the static balance tests before and after the study, but after the Pilates exercises, the results of the Pilates group signifcantly differed from the control group test results when the feet were in shoulder line with open eyes. The results of the dynamic balance after Pilates exercises signifcantly improved in both tests in the study group. Before the study, there were not statistically signifcant differences in the dynamic balance results between the groups. Conclusions. Six-week Pilates exercises had a positive effect on the elderly’s static and dynamic balance.Keywords: Pilates training, static balance, dynamic balance.


1995 ◽  
Vol 73 (12) ◽  
pp. 1765-1773 ◽  
Author(s):  
E. Cafarelli ◽  
F. Liebesman ◽  
J. Kroon

One of the consequences of endurance training is a reduction in force sensation in trained muscles at any exercise intensity. To study the central and peripheral contributions to this adaptation, we trained six male subjects with single-leg cycling at 60% [Formula: see text] peak (30 min/day × 3 days/week × 8 weeks); six others were matched controls. Measurements were made during separate 20-min, single-leg rides at 70% pre-training [Formula: see text] peak, with trained (TR), untrained (UT), and control (CT) legs, before and after training. No pre–post differences were observed in the control group. [Formula: see text] peak increased 18% (p < 0.05) in the TR leg and 6% (p < 0.05) in the UT leg of the trained subjects. Force sensation was significantly less in both the TR (70%; p < 0.05) and UT (50%; p < 0.05) legs during 20 min of single-leg cycling after training. Vastus lateralis EMG, plasma lactate, and heart rate were all significantly (p < 0.05) lower when cycling with either the TR or UT leg, which were both lower than when cycling with the CT leg, at the end of each 20-min ride. These data reflect an intramuscular environment that is better adapted to endurance performance by virtue of both central and peripheral mechanisms. Thus, there is less need to recruit additional motor units to maintain the same power output, and this reduced motor outflow leads to a decline in force sensation.Key words: kinesthesia, proprioception, electromyography, single-leg training, endurance training.


2020 ◽  
Vol 29 (8) ◽  
pp. 1100-1105
Author(s):  
Mohammad H. Izadi Farhadi ◽  
Foad Seidi ◽  
Hooman Minoonejad ◽  
Abbey C. Thomas

Context: Many factors have been reported contributing to altering the neuromuscular function of hip and knee muscles. The lumbar hyperlordosis, as a poor posture in some athletes, is thought to be associated with the alteration of the hip and knee muscles activity. Objective: To examine the activation of selected hip and knee muscles in athletes with and without lumbar hyperlordosis during functional activities. Design: Case-control study. Setting: University laboratory. Participants: Twenty-six college male athletes (n = 13 with and n = 13 without lumbar hyperlordosis). Interventions: Surface electromyography of gluteus maximus (GMAX), gluteus medius (GMED), vastus medialis oblique (VMO), and vastus lateralis (VL) were recorded during single-leg squat and single-leg jump landing (SLJL) tasks. Main Outcome Measure: Preactivity; reactivity; and onset muscle during SLJL and eccentric activity during single-leg squat (GMAX, GMED, VMO, and VL along with the ratio of VMO:VL) were assessed. Results: Athletes with lumbar hyperlordosis had a higher level of activity in their GMAX (P = .003), VMO (P = .04), and VL (P = .01) muscles at the moment before foot contact during SLJL. These athletes also demonstrated a higher level of GMAX activity (P = .01) immediately after foot contact. Finally, athletes with lumbar hyperlordosis activated their GMAX sooner (P = .02) during the SLJL. Athletes with normal lumbar lordosis had more activity in their GMED muscle (P = .001) in the descending phase of the single-leg squat task and a higher VMO:VL (P = .01) at the moment after the foot contact during the SLJL. Conclusion: The altered activation of GMAX, GMED, VMO, VL, and VMO:VL can reveal the role of lumbar hyperlordosis in the knee and hip muscles’ alteration in athletes. Further study is needed to identify whether these alterations in the hip and knee muscles contribute to injury in athletes.


2018 ◽  
Vol 53 (11) ◽  
pp. 1071-1081 ◽  
Author(s):  
Cara L. Lewis ◽  
Hanna D. Foley ◽  
Theresa S. Lee ◽  
Justin W. Berry

ContextWeakness or decreased activation of the hip abductors and external rotators has been associated with lower extremity injury, especially in females. Resisted side stepping is commonly used to address hip weakness. Whereas multiple variations of this exercise are used clinically, few data exist regarding which variations to select.ObjectiveTo investigate differences in muscle-activation and movement patterns and determine kinematic and limb-specific differences between men and women during resisted side stepping with 3 resistive-band positions.DesignControlled laboratory study.SettingLaboratory.Patients or Other ParticipantsA total of 22 healthy adults (11 men, 11 women; age = 22.8 ± 3.0 years, height = 171.6 ± 10.7 cm, mass = 68.5 ± 11.8 kg).Intervention(s)Participants side stepped with the resistive band at 3 locations (knees, ankles, feet).Main Outcome Measure(s)We collected surface electromyography of the gluteus maximus, gluteus medius, and tensor fascia lata (TFL) for the moving and stance limbs during the concentric and eccentric phases. We also measured trunk inclination, hip and knee flexion, and hip-abduction excursion.ResultsHip-abductor activity was higher in women than in men (P ≤ .04). The pattern of TFL activity in the stance limb differed by sex. Women performed the exercise in greater forward trunk inclination (P = .009) and had greater hip excursion (P = .003). Gluteus maximus and medius activity increased when the band was moved from the knees to the ankles and from the ankles to the feet, whereas TFL activity increased only when the band was moved from the knees to the ankles. Findings were similar for both the stance and moving limbs, but the magnitudes of the changes differed.ConclusionsCompared with placing the band around the ankles, placing the band around the feet for resisted side stepping elicited more activity in the gluteal muscles without increasing TFL activity. This band placement is most appropriate when the therapeutic goal is to activate the muscles that resist hip adduction and internal rotation.


2018 ◽  
Vol 27 (2) ◽  
pp. 138-143 ◽  
Author(s):  
John H. Hollman ◽  
Tyler A. Berling ◽  
Ellen O. Crum ◽  
Kelsie M. Miller ◽  
Brent T. Simmons ◽  
...  

Context: Hip extension with hamstring-dominant rather than gluteus maximus-dominant recruitment may increase anterior femoracetabular forces and contribute to conditions that cause hip pain. Cueing methods during hip extension exercises may facilitate greater gluteus maximus recruitment. Objective: We examined whether specific verbal and tactile cues facilitate gluteus maximus recruitment while inhibiting hamstring recruitment during a bridging exercise. Design: Randomized controlled trial. Setting: Biomechanics laboratory. Participants: 30 young adult women (age 24 [3] y; BMI 22.2 [2.4] kg/m2). Intervention: Participants were tested over 2 sessions, 1 week apart, while performing 5 repetitions of a bridging exercise. At their second visit, participants in the experimental group received verbal and tactile cues intended to facilitate gluteus maximus recruitment and inhibit hamstring recruitment. Control group participants received no additional cues beyond original instructions. Main Outcome Measures: Gluteus maximus and hamstring recruitment were measured with surface electromyography, normalized to maximal voluntary isometric contractions (MVICs). Results: Gluteus maximus recruitment was unchanged in the control group and increased from 16.8 to 33.0% MVIC in the cueing group (F = 33.369, P < .001). Hamstring recruitment was unchanged in the control group but also increased from 16.5 to 29.8% MVIC in the cueing group (F = 6.400, P = .02). The effect size of the change in gluteus maximus recruitment in the cueing group (Cohen’s d = 1.5, 95% CI = 0.9 to 2.2) was not significantly greater than the effect size in hamstring recruitment (Cohen’s d = 0.8, 95% CI = 0.1 to 1.5). Conclusions: Verbal and tactile cues hypothesized to facilitate gluteus maximus recruitment yielded comparable increases in both gluteus maximus and hamstring recruitment. If one intends to promote hip extension by facilitating gluteus maximus recruitment while inhibiting hamstring recruitment during bridging exercises, the cueing methods employed in this study may not produce desired effects.


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