Effect of side-sling plank exercise on trunk and hip muscle activation in subjects with gluteus medius weakness

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.

Optimized Torque Assistance During Walking With an Idealized Hip Exoskeleton

The hip muscles account for a great percentage of the total human energy expenditure during walking and many wearable devices have been developed in assisting the hip joint to reduce the metabolic Cost Of Transport (COT) for walking. However, the effectiveness of assisting the hip in only one direction (either flexion or extension) or both directions has not been systematically studied and the underlying muscle mechanics and energetics affected by the assistance are not well understood. In this study, human-exoskeleton simulation based optimizations were performed to find optimized hip assistance torque profiles for (1) unidirectional flexion assistance, (2) unidirectional extension assistance, and (3) bidirectional flexion and extension assistance. Our results show that the bidirectional assistance is the most effective in reducing the COT of walking (22.7% reduction) followed by flexion (19.2%) and extension (11.7%). The flexion assistance resulted in more COT saving than the output of its net work by 35.9%, which indicates that the negative work done (42.2% of its positive counterpart) also played an important role in reducing the COT. The bidirectional assistance also reduced the activations of the hip extensors to a great extent and shifted the activation pattern of the hip flexor (ilipsoas). These results can provide valuable information for optimal hip actuation (timing and profiles) and help exoskeleton designers make informed decisions.

A self-oblique exercise that activates the coordinated activity of abdominal and hip muscles–A pilot study

The importance of an interaction between trunk stability muscles and hip muscle function has been suggested. However, reported exercises rarely act on the trunk and hip muscles simultaneously. Here, we devised an abdominal oblique and hip muscle exercise, the Self-oblique exercise (SOE). We examined whether SOE activated abdominal and hip muscles in the supine and half-kneeling positions, compared with abdominal crunch (AC) and plank exercises; and whether participants could modulate the exercise load. Participants were 20 healthy males with some sports experience such as football and baseball on average 10.5 ± 4.0 years. Participants applied self-pressure to their right thighs using the contralateral upper limb with 40% or 70% of the maximum force in Supine SOE and Half- kneeling SOE. The following abdominal and hip muscles were measured using surface electromyography: bilateral external obliques (EO), bilateral internal obliques (IO), right rectus abdominis, right gluteus medius (GMed), and right adductor longus (ADD). All evaluated muscle groups showed significant differences between exercises (p < 0.001). Supine SOE-70% showed 80.4% maximal voluntary contraction (MVC) for left EO (p < 0.017), 61.4% MVC for right IO (p < 0.027), 24.3% MVC for GMed (p < 0.002), and 42.4% MVC for ADD (p < 0.004); these were significantly greatest among all exercises. Muscle activity during Supine SOE-70% was greater than that during Supine SOE-40%. Similarly, Half-kneeling SOE-40% promoted abdominal and hip muscle exertion, and showed more significant activity in GMed (p < 0.006) and ADD (p < 0.001) than AC and plank. SOE could activate abdominal and hip muscles depends on the pressure applied by upper limb. Also, SOE allows participants to modulate the exercise load in a self-controlled step by step manner. Modulation of the exercise load is difficult in AC or plank compared to SOE, and AC or plank cannot obtain simultaneous oblique and hip muscle activity. SOE could be practiced anywhere, in various positions, without any tools.

Effect of Hip Abductors and Lateral Rotators Muscle Strengthening on Pain and Functional Outcome in Patients with Patellofemoral Pain: Systematic Review and Meta-Analysis

Background: This study systematically reviews and Meta-analyses the best-published evidence on the therapeutic value of strengthening hip abductors and lateral rotators muscles for the treatment of Patellofemoral Pain (PFP) with a presumptive hypothesis that strengthening hip muscles stabilises the patellofemoral joint, relieves pain and enhances knee functions.Methodology: Electronic database searches of Medline, EMBASE, CINAHL, PEDro and PubMed Central between January 1994 and September 2019 using PICOS tool. The methodological quality of the selected studies was appraised individually using the 20-item McMaster Critical Review Form for Quantitative Studies. Supplemental quality appraisal of randomized controlled clinical trials performed using the Cochrane Collaboration's 'Risk of bias' quality criteria. Data on patient population demographics, interventions, duration of intervention and outcome measures were extracted, summarized in evidence tables and descriptive analysis made. Pooled effects size from appropriate RCTs was determined by meta-analysis under both fixed and random-effects models.Results: All included fourteen studies demonstrated that hip muscles strengthening resulted in improved pain and knee function. All RCTs, except one, demonstrated that hip muscles strengthening is superior to quadriceps strengthening. Of the five RCTs accessing the surplus effect of hip-quad versus quadriceps strengthening, four suggested that hip-quad strengthening is superior over the standard quadriceps strengthening alone to improve PFP and knee function.Conclusion and Implications: In patients with PFP, strengthening of hip abductors and lateral rotators have greater therapeutic significance than the conventional quadriceps exercises in improving knee pain and function both in the short- and long term. However, caution is required, because a standardized hip-quad protocol is yet to be developed, which warrants further studies. Systematic review registration:There was no protocol prepared and no amendments were present. This systematic review is registered under Open Science framework, with following registration digital object identifier 10.17605/OSF.IO/CWZ8V

Is Hip Muscle Strength Associated with Dynamic Knee Valgus in a Healthy Adult Population? A Systematic Review

This study aimed to systematically review research investigating the association between hip muscle strength and dynamic knee valgus (DKV). Four databases (MEDLINE, PubMed, CINAHL, and SPORTDiscus) were searched for journal articles published from inception to October 2020. Seven studies investigating the association between hip muscle strength and DKV using a two-dimensional motion analysis system in healthy adults were included. The relationship between hip abductor muscle strength and DKV was negatively correlated in two studies, positively correlated in two studies, and not correlated in three studies. The DKV was associated with reduced hip extensor muscle strength in two studies and reduced hip external rotator muscle strength in two studies, while no correlation was found in three and five studies for each muscle group, respectively. The relationship between hip muscle strength, including abductors, extensors, and external rotators and DKV is conflicting. Considering the current literature limitations and variable methodological approaches used among studies, the clinical relevance of such findings should be interpreted cautiously. Therefore, future studies are recommended to measure the eccentric strength of hip muscles, resembling muscular movement during landing. Furthermore, high-demand and sufficiently challenging functional tasks revealing lower limb kinematic differences, such as cutting and jumping tasks, are recommended for measuring the DKV.

Muscle activation during single leg squat is affected by position of the nonstance limb

ABSTRACT Context: The single leg squat (SLS) is appropriate for targeting activation, strengthening, and/or neuromuscular retraining of the gluteus maximus, gluteus medius, and quadriceps. However, the effect of different non-stance leg positions on muscle activity has not been fully evaluated. Objective: To compare the muscle activity of selected stance leg hip muscles during the SLS with 3 non-stance leg positions: in front, in the middle, and in back. Design: Controlled laboratory study. Setting: Biomechanics laboratory. Participants: Seventeen healthy adults. Main Outcome Measure(s): Surface EMG data of the gluteus maximus, gluteus medius, lateral hamstrings, medial hamstrings, rectus femoris, and TFL as well as kinetic data of the hip and knee were collected while participants performed the 3 SLS tasks. Mean muscle activation levels during the descent phase and ascent phase for the selected hip muscles were compared for the 3 tasks. Hip and knee kinetics in all 3 planes were also compared for the 3 tasks. Each variable of interest was analyzed using a separate linear regression model with a generalized estimating equations correction. Results: Muscle activation levels of the gluteus maximus, gluteus medius, medial hamstrings, rectus femoris, and TFL on the stance leg during descent, and the medial hamstrings and TFL during ascent were significantly different between SLS tasks. The greatest number of differences occurred between SLS-Front and SLS-Back. During descent, gluteal muscle activity was greater in SLS-Front and SLS-Middle than in SLS-Back. For both phases, TFL activity was greater during SLS-Front than both SLS-Middle and SLS-Back. Kinetic differences at the hip and knee between SLS tasks were also observed. Conclusion: The 3 SLS tasks have different muscle activation and kinetic profiles. Clinician and researchers can vary non-stance leg position during the SLS to manipulate muscle activation levels and tailor the exercise to assist with goals at different stages of rehabilitation.

Early biomechanical outcome in patients with acetabular fractures treated using the pararectus approach: a gait and stair climb analysis study

Purpose Patients with surgically treated acetabular fractures using extensive dissection of hip muscles demonstrate an incomplete biomechanical recovery and limited joint mobility during movement. The purpose of this study was to evaluate the early biomechanical outcome in a series of patients with acetabular fractures treated using the less invasive anatomical pararectus approach. Methods Eight patients (48 ± 14 years, BMI 25.8 ± 3 kg/m2) were investigated 3.8 ± 1.3 months after surgery and compared to matched controls (49 ± 13 years, BMI 26 ± 2.8 kg/m2). Trunk and lower extremity kinematics and kinetics during gait and stair climb were calculated. SF-12 and the Merle d’Aubigné score were used for functional evaluation. Statistical analysis was conducted using Mann–Whitney test and Student’s t test. Effect sizes were calculated using Cohen’s d. Results No group differences for lower extremity kinematics during walking and stair climbing were found. During walking, patients showed significant reductions (p < 0.05) of the vertical ground reaction force (8%) and knee and hip extension moments (29 and 27%). Ipsilateral trunk lean was significantly increased by 3.1° during stair descend while reductions of vertical ground reaction force were found for stair ascend (7%) and descend (20%). Hip extension moment was significantly reduced during stair descend by 37%. Patients revealed acceptable SF-12 physical and mental component outcomes and a good rating for the Merle d’Aubigné score (15.9 ± 1.7). Conclusion Patients showed some biomechanical restrictions that can be related to residual deficits in weight bearing capacity and strength of the hip muscles. In contrast, an immediate recovery of mobility was achieved by preserving lower extremity and pelvic movement. Therefore, the pararectus approach can serve as a viable strategy in the surgical treatment of acetabular fractures. Clinical trial Trial registration number DRKS00011308, 11/14/2016, prospectively registered.

Microelement (Mn, Zn, Cu, Fe, Co, І) levels in quails and their eggs according to their forms and dosage in poultry diet

The paper presents a fragment of a systemic study on the efficiency of replacing inorganic salts of microelements in guaranteed mineral premixes used in quail feed with a complex supplement of said elements in nanocitrate form produced by Nanomaterials and Nanotechnologies LLC (Kyiv). The study is, in particular, focused on the levels of microelements (Mn, Zn, Cu, Fe, Co, І) in quails and their egg yolks depending on the form and concentration of those microelements in the poultry diet. The tests have been conducted on 14-day old Pharaoh quails divided into three groups. Raising conditions – cages. Test duration – 2 months. Quails of all groups were fed complete feed with a balanced content of nutrients and biologically active compounds. Control group birds were given mineral premix containing inorganic salts of (g/t of feed): Mn – 50, Zn ‒ 50, Cu ‒ 2.5, Fe ‒10, Co ‒1 and І ‒ 0.7. Test group quails were fed a mineral complex of aqua citrates of the same elements with a concentration of (calculated for each element) 1/10 (D1) and 1/20 (D2) or 10 and 5 % of their content in a standard mineral premix (SP). It is established that the form and dosage of microelements introduced into the diet affect their levels in quails and their egg yolks. Nanocitrates of bioelements have a relatively high cumulative potential in poultry compared with the control group (an inorganic form of microelements). The best results are achieved with citrate elements being fed in a concentration of 10% of their regular content in a standard mineral premix. It is proven that the use of optimal concentration of aqua citrates of microelements in poultry diet promotes increased levels of manganese, iron, zinc, copper and cobalt (Р < 0.05‒0.001) in the liver and hip muscles as well as iron and copper levels (Р < 0.01‒0.001) in breast muscles of quails; increased body weight by 15.7 % during the testing period; an enhanced biological value of the eggs (increased calcium (Р < 0.05), iodine (Р < 0.05), zinc (Р < 0.01) levels) compared to analogs in the control group.

Optimizing the Femoral Offset for Restoring Physiological Hip Muscle Function in Patients With Total Hip Arthroplasty

ObjectiveFemoral offset (FO) restoration is significantly correlated with functional recovery following total hip arthroplasty (THA). Accurately assessing the effects of FO changes on hip muscles following THA would help improve function and optimize functional outcomes. The present study aimed to (1) identify the impact of FO side difference on the hip muscle moment arms following unilateral THA during gait and (2) propose the optimal FO for a physiological hip muscle function.MethodsIn vivo hip kinematics from eighteen unilateral THA patients during gait were measured with a dual-fluoroscopic imaging system. The moment arms of thirteen hip muscles were calculated using CT-based 3D musculoskeletal models with the hip muscles’ lines of actions. The correlation coefficient (R) between FO and hip muscle moment arm changes compared with the non-implanted hip was calculated. We considered that the FO reconstruction was satisfactory when the abductor moment arms increased, while the extensor, adductor, and flexor moment arms decreased less than 5%.ResultsA decreased FO following THA was significantly correlated with a decrease of the abductor and external rotator moment arms during the whole gait (R &gt; 0.5) and a decrease of extensor moment arms during the stance phase (R &gt; 0.4). An increased FO following THA was significantly associated with shorter flexor moment arms throughout the gait (R &lt; −0.5) and shorter adductor moment arms in the stance phase (R &lt; −0.4). An increase in FO of 2.3–2.9 mm resulted in increased abductor moment arms while maintaining the maximum decrease of the hip muscles at less than 5.0%.ConclusionAn increase of 2–3 mm in FO could improve the abductor and external rotator function following a THA. Accurate surgical planning with optimal FO reconstruction is essential to restoring normal hip muscle function in THA patients.