Anatomical and functional specializations of the human gluteus maximus

Many anthropologists and anatomists have claimed that the human gluteus maximus is a functionally and structurally unique muscle, but there is not agreement on the actual characteristics of the muscle which do distinguish man from other primates. In this paper the superficial gluteus in a wide range of primates is discussed and those traits entirely unique to man are identified. The morphological specializations of the human gluteus maximus are confined to its cranial portion. This part is thicker in man than in any other primate; it has a new and firm origin, a modified ascending tendon of insertion, and an additional new insertion into the overlying fascia lata. Such changes improve the ability of the gluteus maximus to participate in controlling lateral stability of the trunk, and it suggested that this is the function which has been selected for in human evolution.     

The expansive gluteus maximus flap

The rich vascular network of the gluteal and posterior thigh region provides for a larger range of flaps for reconstructive surgery than previously described. Facility with these flaps requires an appreciation of relevant anatomy, embryology, and anthropology. Structural changes in the gluteus maximus muscle are critical to the evolutionary advance toward an upright stance during walking. The superficial and deep segmentation of the gluteus maximus are best appreciated by phylogenic and ontogenetic study. Femoral arterial and gluteal arterial anastomotic hemodynamics are affected by the relative involution of the gluteal system in late embryogenesis. The gluteal thigh flap should include contributions from the femoral system when the cutaneous branch of the inferior gluteal artery cannot be identified. Huge sacral wounds can be closed with gluteus maximus myocutaneous flaps with maintenance of muscular function by detaching the entire origin, sliding the muscle medially, and reconstructing these attachments. By dissection between the divergent inserting fibers of the gluteus maximus, a long, superficial portion of the muscle can be raised that forms the basis of the extended gluteus maximus flap. The pedicle of the flap is at the level of the piriformis muscle and the skin paddle can be placed over the midportion of the posterior thigh. Finally, the first deep femoral perforating artery forms the basis of a posterolateral fasciae latae flap that is well suited for coverage of defects over the trochanter.     

Succinic dehydrogenase and cholinesterase activities in the skeletal muscles of the desert rat and the albino rat

The deltoid and gluteus maximus of the desert rat and the albino rat were examined histochemically for the distribution of succinic dehydrogenase (SDH) and cholinesterase (ChE). SDH activity showed that the deltoid and gluteus maximus muscles of the two animals consisted of three types of muscle fibres, with a predominance of muscle fibres that have higher SDH activity in both the deltoid and gluteus maximus muscles of the desert rat than in the albino rat. The mean diameter of all muscle fibres in the deltoid and gluteus maximus muscles and their ratios to the average body weight were determined in both animals. The desert rat showed a statistically significant increase in those ratios compared with the corresponding ratios for the albino rat. ChE activity showed that the deltoid and gluteus maximus muscles are richly innervated by intensely positive ChE motor end-plates with a predominance of plaque-like terminals. The mean diameters of the end-plates and the ratios of these diameters to the diameter of the muscle fibres together with their ratios to the body weight were determined. A correlation between these values and the histological findings is proposed.     

In vivo moment arm lengths for hip extensor muscles at different angles of hip flexion

Moment arm lengths of three hip extensor muscles, the gluteus maximus, the hamstrings and the adductor magnus, were determined at hip flexion angles from 0 degrees to 90 degrees by combining data from ten autopsy specimens and from twenty patients, the latter examined by computed tomography. A straight-line muscle model for muscle force was used for the hamstrings and adductor magnus, and for the gluteus maximus a two-segment straight-line muscle force model was used. With the joint in its anatomical position the moment arm of the gluteus maximus to the bilateral motion axis averaged 79 mm, for the hamstrings 61 mm and for the adductor magnus 15 mm. The moment arm of gluteus maximus decreased with increasing hip flexion angle. The hamstrings showed an increase in moment arm length up to an average of 35 degrees hip flexion and then a decrease with increasing hip flexion angle. The corresponding figures for the adductor magnus moment arm showed an increase up to 75 degrees and then a decrease. Statistical analysis revealed significant differences in moment arm length between men and women.     

Gluteus maximus adipomuscular turnover or sliding flap in the surgical treatment of extensive sacral chordomas

Two cases with extensive posterior peritoneal defects after high sacral amputation for sacral chordoma are presented. An adipomuscular flap as a modification of the conventional gluteus maximus muscle flap was designed to obliterate an extensive residual posterior peritoneal dead space. The deep adipose tissue beneath the superficial fascia left on the gluteus maximus muscle was effectively used to provide more volume to the flap. The adipomuscular flap was turned over into the posterior peritoneal defect in the first case, and the flap was slid into the cavity in the other case. The adipomuscular flap eventually enabled the successful reconstruction of the posterior peritoneal defect, and the volume of the flap was well maintained behind the rectum, according to the postoperative magnetic resonance imaging findings in both cases.     

Lower-limb muscle function during sidestep cutting

To investigate lower-limb muscle function during sidestep cutting, prior studies have analysed electromyography (EMG) data together with three dimensional motion analysis. Such an approach does not directly quantify the biomechanical role of individual lower-limb muscles during a sidestep cut. This study recorded three dimensional motion analysis, ground reaction force (GRF) and EMG data for eight healthy males executing an unanticipated sidestep cut. Using a musculoskeletal modelling approach, muscle function was determined by computing the muscle contributions to the GRFs and lower-limb joint moments. We found that bodyweight support (vertical GRF) was primarily provided by the vasti, gluteus maximus, soleus and gastrocnemius. These same muscles, along with the hamstrings, were also primarily responsible for modulating braking and propulsion (anteroposterior GRF). The vasti, gluteus maximus and gluteus medius were the key muscles for accelerating the centre-of-mass towards the desired cutting direction by generating a medially-directed GRF. Our findings have implications for designing retraining programs to improve sidestep cutting technique.     

Effect of abdominal drawing-in maneuver during hip extension on the muscle onset time of gluteus maximus,hamstring, and lumbar erector spinae in subjects with hyperlordotic lumbar angle

Background

The abdominal drawing-in maneuver (ADIM) is used to prevent abnormal movements of the lumbar spine and pelvis during therapeutic exercises. This study compared the effects of ADIM on the muscle onset time of the hamstring, gluteus maximus, and erector spinae muscles during prone hip extension exercise in subjects with or without hyperlordotic lumbar angle. Forty healthy adults (18 male, 22 female) were recruited for this study.

Methods

The lumbar lordotic angles and pelvic tilt angles of the subjects were measured using the Avaliação postural analysis software. The subjects were divided into two groups: the lumbar hyperlordotic angle (LHLA) and lumbar normal lordotic angle (LNLA) groups. The muscle contraction onset time of the hamstring, gluteus maximus, and erector spinae were assessed using surface electromyography.

Results

During ADIM application, the muscle contraction onset time of the gluteus maximus was significantly increased in the LHLA group compared with the LNLA group.

Conclusions

ADIM application during prone hip extension was more effective for gluteus maximus onset time in the LHLA group. Therefore, ADIM during prone hip extension may be useful for gluteus maximus training in individuals with lumbar hyperlordosis.     

Variation of rotation moment arms with hip flexion.

Excessive flexion and internal rotation of the hip is a common gait abnormality among individuals with cerebral palsy. The purpose of this study was to examine the influence of hip flexion on the rotational moment arms of the hip muscles. We hypothesized that flexion of the hip would increase internal rotation moment arms and decrease external rotation moment arms of the primary hip rotators. To test this hypothesis we measured rotational moment arms of the gluteus maximus (six compartments), gluteus medius (four compartments), gluteus minimus (three compartments) iliopsoas, piriformis, quadratus femoris, obturator internus, and obturator externus. Moment arms were measured at hip flexion angles of 0, 20, 45, 60, and 90 degrees in four cadavers. A three-dimensional computer model of the hip muscles was developed and compared to the experimental measurements. The experimental results and the computer model showed that the internal rotation moment arms of some muscles increase with flexion; the external rotation moment arms of other muscles decrease, and some muscles switch from external rotation to internal rotation as the hip is flexed. This trend toward internal rotation with hip flexion was apparent in 15 of the 18 muscle compartments we examined, suggesting that excessive hip flexion may exacerbate internal rotation of the hip. The gluteus maximus was found to have a large capacity for external rotation. Enhancing the activation of the gluteus maximus, a muscle that is frequently underactive in persons with cerebral palsy, may help correct excessive flexion and internal rotation of the hip.     

Are there neuromuscular differences on proximal and distal joints in patellofemoral pain people? A systematic review and meta-analysis

We aim to determine the neuromuscular differences in proximal and distal joints between patellofemoral pain (PFP) and healthy participants. Relevant articles were selected through seven databases. Studies comparing electromyography (EMG) or morphology parameters of trunk, hip, ankle/foot joints in PFP people compared to a healthy control group (CG) were included. 1458 studies were identified, from which 36 were included in the systematic review [PFP, n = 655; CG, n = 649] (31 involving EMG) and 32 in the meta-analysis (27 involving EMG). 75% of studies presented moderate to high methodological quality. The meta-analysis demonstrated that, compared to CG, PFP have: (i) similar transversus abdominis/internal oblique and erector spinae muscle onset, independently of sex; (ii) similar EMG amplitude of gluteus medius and gluteus maximus, independently of sex or task performed; (iii) similar gluteus medius muscle onset, independently of sex or task performed; (iv) similar gluteus maximus muscle onset, independently of sex; (v) a small effect for a shorter activation duration of gluteus medius (0.50; 95% CI [0.07; 0.93]; p = 0.02); (vi) a medium effect for a shorter activation duration of gluteus medius during stair/step down task (0.81; 95% CI [0.18; 1.45]; p = 0.01); (vii) similar external oblique, gluteus maximus, tensor fascia latae, tibialis anterior and fibularis muscle thickness and (viii) a small effect for a smaller gluteus medius muscle thickness (0.52; 95% CI [0.22; 0.82]; p = 0.007). We were not able to perform meta-analysis for EMG at distal joints. Neuromuscular differences in PFP seems to occur only in the gluteus medius muscle. Due to high heterogeneity and several methodological concerns observed, mainly in EMG studies, the interpretation of these results needs caution.     

Gluteus maximus muscle function and the origin of hominid bipedality

Bipedality not only frees the hands for tool use but also enhances tool use by allowing use of the trunk for leverage in applying force and thus imparting greater final velocity to tools. Since the weight and acceleration of the trunk and forelimbs on the hindlimbs must be counteracted by muscles such as m. gluteus maximus that control pelvic and trunk movements, it is suggested that the large size of the cranial portion of the human gluteus maximus muscle and its unique attachment to the dorsal ilium (which is apparent in the Makapan australopithecine ilium) may have contributed to the effectiveness with which trunk movement was exploited in early hominid foraging activities. To test this hypothesis, the cranial portions of both right and left muscles were investigated in six human subjects with electromyography during throwing, clubbing, digging, and lifting. The muscles were found to be significantly recruited when the trunk is used in throwing and clubbing, initiating rotation of the pelvis and braking it as trunk rotation ceases and the forelimb accelerates. They stabilize the pelvis during digging and exhibit marked and prolonged activity when the trunk is maintained in partial flexion during lifting of heavy objects.     

The distally-based gluteus maximus muscle flap.

We describe a distally-based gluteus maximus muscle flap to cover trochanteric pressure sores. The results in 4 patients have been gratifying.     

Distal perforator-based fasciocutaneous V-Y flap for treatment of sacral pressure ulcers

Although the gluteal V-Y advancement flap has been recognized as the most reliable method for management of sacral pressure ulcers, its limited mobility has been a challenging problem. The authors present a new modification of the V-Y advancement flap to overcome the problem. After débridement, a large triangle is designed to create a V-Yadvancement flap on the unilateral buttock and the medial half is elevated as a fasciocutaneous flap, preserving the distal perforators in the muscular attachment. Then an arc-shaped incision is made in the gluteus maximus muscle along with the lateral edge of the triangular flap. The split muscle is elevated at a depth above the deeper fascia until sufficient advancement of the flap is obtained. This full-thickness elevation of the gluteus maximus muscle from the distal (lateral) side avoids the impairment of perforators or their mother vessels and achieves great advancement. Thirty-one patients with sacral pressure defects larger than 8 cm in diameter were treated using this surgical procedure. Overall, 93.5 percent of the flaps (29 of 31) healed primarily. The largest defect that was closed with a unilateral flap was 16 cm in diameter. The present technique accomplishes remarkable excursion of the unilateral V-Y fasciocutaneous flap, with high flap reliability and preservation of the contralateral buttock as well as gluteus maximus muscle function.     

The morphology of the gluteus maximus during human evolution: Prerequisite or consequence of the upright bipedal posture?

The human gluteus maximus differs from that of the other hominoids because of its size and bony attachments. These differences raise questions concerning their sequence of appearance in human evolution. Given that humans practice a unique locomotor style, one wonders if the human gluteus maximus morphology is a prerequisite or a consequence of upright bipedal locomotion. This question is addressed using a computer model that evaluates muscle leverage in a variety of locomotor postures. In this model, the human-like, or ape-like, muscular pattern is imposed upon a representative hindlimb of each of the five extant hominoids. Shapes of the skeletal elements (i.e. ilium and ischium lengths) are adjusted in the computer to simulate an evolutionary progression from an ape to a human skeletal morphology. Changes in the leverage of different parts of the gluteus maximus (measured as moment arms) are monitored during this transition. The results show how the mechanical leverages of the gluteus maximus would have changed in a variety of hypothetical evolutionary sequences that describe an ape to human transition. Although the hominoid models exhibit minor differences in these simulations, they all show that the postural and locomotor functions of the gluteus maximus would become more difficult if musculoskeletal morphology changed to the human-like pattern before erect bipedal posture was adopted. Conversely, small adjustments in the ape-like musculoskeletal condition support an erect bipedal posture. These results suggest that a human like posture would have preceded the appearance of the human-like musculoskeletal morphology. Human gluteal morphology, therefore, is a consequence and not a prerequisite of the upright bipedal posture.     

Comparative and functional morphology of musculus canalis ani in tetrapod mammals and primates]

Comparative anatomy of structure and function of the M. canalis ani in tetrapode mammals and primates is described for the first time. The muscle itself lies on the sphincter ani internus in the area between the anorectal ("pectinate") and anocutaneal ("white") lines and its circumference is intact around the entire anal canal. The canalis ani muscle orginates from the superior part of the sphincter ani internus and concomitantly receives additional fibers from the longitudinal muscle. Caudally the muscle dips back into the sphincter ani internus and, at the same time, a small portion of the fibers go to the longitudinal muscle and, likewise, a portion also sets itself on the perinaal skin. On the basis of its morphological relationship to the convoluted vessels of the rectal venous plexus, the canalis ani muscle appears to be able to complete the closing of the anus in the continence phase to such an extent that a complete closing of the anal lumen is guaranted.     

Balance of hip and trunk muscle activity is associated with increased anterior pelvic tilt during prone hip extension

Prone hip extension has been used as a self-perturbation task to test the stability of the lumbopelvic region. However, the relationship between recruitment patterns in the hip and trunk muscles and lumbopelvic kinematics remains unknown. The present study aimed to examine if the balance of hip and trunk muscle activities are related to pelvic motion and low back muscle activity during prone hip extension. Sixteen healthy participants performed prone hip extension from 30° of hip flexion to 10° of hip extension. Surface electromyography (of the gluteus maximus, semitendinosus, rectus femoris, tensor fasciae latae, multifidus, and erector spinae) and pelvic kinematic measurements were collected. Results showed that increased activity of the hip flexor (tensor fasciae latae) relative to that of hip extensors (gluteus maximus and semitendinosus) was significantly associated with increased anterior pelvic tilt during hip extension (r=0.52). Increased anterior pelvic tilt was also significantly related to the delayed onset timing of the contralateral and ipsilateral multifidus (r=0.57, r=0.53) and contralateral erector spinae (r=0.63). Additionally, the decrease of the gluteus maximus activity relative to the semitendinosus was significantly related to increased muscle activity of the ipsilateral erector spinae (r=-0.57). These results indicate that imbalance between the agonist and antagonist hip muscles and delayed trunk muscle onset would increase motion in the lumbopelvic region.     

Gluteus maximus myocutaneous flaps for repair of pressure sores.

Myocutaneous flaps based on the gluteus maximus muscle, and its blood supply, have many advantages for the surgical repair of pressure sores in paraplegics. These are described, as well as the techniques used in various areas.     

A reliable approach to the closure of large acquired midline defects of the back

A systematic regionalized approach for the reconstruction of acquired thoracic and lumbar midline defects of the back is described. Twenty-three patients with wounds resulting from pressure necrosis, radiation injury, and postoperative wound infection and dehiscence were successfully reconstructed. The latissimus dorsi, trapezius, gluteus maximus, and paraspinous muscles are utilized individually or in combination as advancement, rotation, island, unipedicle, turnover, or bipedicle flaps. All flaps are designed so that their vascular pedicles are out of the field of injury. After thorough debridement, large, deep wounds are closed with two layers of muscle, while smaller, more superficial wounds are reconstructed with one layer. The trapezius muscle is utilized in the high thoracic area for the deep wound layer, while the paraspinous muscle is used for this layer in the thoracic and lumbar regions. Superficial layer and small wounds in the high thoracic area are reconstructed with either latissimus dorsi or trapezius muscle. Corresponding wounds in the thoracic and lumbar areas are closed with latissimus dorsi muscle alone or in combination with gluteus maximus muscle. The rationale for systematic regionalized reconstruction of acquired midline back wounds is described.     

Analysis of muscle activation during different leg press exercises at submaximum effort levels

Many studies have analyzed muscle activity during different strength exercises. Although the leg press (LP) is one of the most common exercises performed, there is little evidence of lower limb muscle activity patterns during this exercise and its variations. Thus, this study aimed to verify how mechanical changes and loads affect lower limb muscle activity during the performance of different LP exercises. Fourteen women performed 3 LP exercises: 45 degrees LP (LP45), LP high (LPH), and LP low (LPL) at 40% and 80% of the 1 repetition maximum. The electromyographic activity of the rectus femoris, vastus lateralis, biceps femoris, gastrocnemius, and gluteus maximus was recorded. Results suggested that mechanical changes affect lower limb muscle activity and that it is related to the load used. At moderate effort levels, the rectus femoris and gastrocnemius were more active during the LP45 and LPL than during the LPH. At a high effort level, the rectus femoris and vastus lateralis (quadriceps) were more active during the LPL than the LPH. Again, the rectus femoris and gastrocnemius were more active during the LP45 and LPL than the LPH. On the other hand, gluteus maximus activity was greater during the LPH than the LPL. This study found that coordination patterns of muscle activity are different when performing LP variations at high or moderate effort levels because of mechanical changes and different loads lifted during the different LP exercises. These results suggest that if the goal is to induce greater rectus femoris and vastus lateralis (quadriceps) activation, the LPL should be performed. On the other hand, if the goal is to induce gluteus maximus activity, the LPH should be performed.     

Effect of sex hormones on neuromuscular control patterns during landing.

The purpose of the study was to investigate the effects of sex hormones across menstrual cycle phases on lower extremity neuromuscular control patterns during the landing phase of a drop jump. A repeated-measures design was utilized to examine sex hormone effects in 26 recreationally active eumenorrheic women. Varus/valgus knee angle and EMG activity from six lower extremity muscles were recorded during three drop jumps from a 50 cm platform in each phase of the menstrual cycle. Blood assays verified sex hormone levels and cycle phase. The semitendinosus muscle exhibited onset delays (p0.006) relative to ground contact during the luteal phase, and demonstrated a significant (p0.05) difference between early and late follicular phases. Muscle timing differences between the gluteus maximus and semitendinosus were decreased (p0.05) in the luteal compared to early follicular phases. These results suggest a different co-contractive behavior between the gluteus maximus and semitendinosus, signifying a shift in neuromuscular control patterns. It appears that female recreational athletes utilize a different neuromuscular control pattern for performing a drop jump sequence when estrogen levels are high (luteal phase) compared to when they are low (early follicular phase).     

The nontypical gluteus maximus flap

Since 1984, 42 patients have been treated with gluteus maximus myocutaneous flaps. In 37 patients, a "classical" gluteus maximus myocutaneous flap was used to cover a sacral-gluteal defect. In 5 patients, a "nontypical" gluteus maximus myocutaneous flap was used: two flaps were advanced from caudal to cranial to close defects over the lumbar spinal area, two flaps were advanced from cranial to caudal to close defects in the perineal region, and one flap was advanced from medial to lateral to close a trochanteric defect. All defects could be closed. There was no flap necrosis. In 12 patients (out of 42) there were minor wound infections, and in 6 patients there were minor wound dehiscences. The average blood loss never exceeded 500 cc, the average time of hospitalization (postoperatively) was 17 days, and mobilization (walking) was started 3 to 4 days postoperatively. The average distance of flap advancement was 10 cm. The maximum defect closed by a bilateral V-Y gluteus maximus myocutaneous flap was 24 x 20 cm.