Foetal development of the human gluteus maximus muscle with special reference to its fascial insertion

Abstract

The human gluteus maximus muscle (GMX) is characterised by its insertion to the iliotibial tract (a lateral thick fascia of the thigh beneath the fascia lata), which plays a critical role in lateral stabilisation of the hip joint during walking. In contrast, in non-human primates, the GMX and biceps femoris muscle provide a flexor complex. According to our observations of 15 human embryos and 11 foetuses at 7-10 weeks of gestation (21-55 mm), the GMX anlage was divided into 1) a superior part that developed earlier and 2) a small inferior part that developed later. The latter was adjacent to, or even continuous with, the biceps femoris. At 8 weeks, both parts inserted into the femur, possibly the future gluteal tuberosity. However, depending on traction by the developing inferior part as well as pressure from the developing major trochanter of the femur, most of the original femoral insertion of the GMX appeared to be detached from the femur. Therefore, at 9-10 weeks, the GMX had a digastric muscle-like appearance with an intermediate band connecting the major superior part to the small inferior mass. This band, most likely corresponding to the initial iliotibial tract, extended laterally and distally far from the muscle fibres. The fascia lata was still thin and the tensor fasciae latae seemed to develop much later. It seems likely that the evolutionary transition from quadripedality to bipedality and a permanently upright posture would require the development of a new GMX complex with the iliotibial tract that differs from that in non-human primates. (Folia Morphol 2018; 77, 1: 144-150).

Suboccipital myodural bridges revisited: Application to cervicogenic headaches

“…In effective attachments of striated muscle fibers, any muscle-covering fascia would play a role in pulling up the target, including the skeleton: a well-known example is the tensor fasciae latae and gluteus maximus muscles, which allow strong stretching of the iliotibial band for lateral knee stabilization (Gerlach and Lierse, 1990). In contrast to the striated muscle fibers oriented along the supero-inferior AX of the lower extremity to reach a developing iliotibial band (Cho et al, 2018b;Shiraishi et al, 2018), muscle fibers of the Rma and Oci differed in direction from the candidate Type 1 myodural bridges, the latter of which requires a pull-up vector. Thus, the power of muscle contraction was most likely conducted to collagen fibers in the bridge after a reduction and change of direction.…”

Development and growth of the foot lumbricalis muscle: a histological study using human foetuses

“…Fetal development of the muscle-tendon interface has been one of the leading topics in anatomical research [1,2,22]. In contrast to the concept of the definite connection between the muscle and tendon, our group has demonstrated a delayed morphological change at the origin or insertion of human fetus striated muscles at multiple sites [5,9,11,12,16,21]. Because an anchoring of striated muscle fiber to a collagen bundle requires a large molecular complex including dystrophin, desmin, nitric oxide synthese, and other proteins, a destruction and rebuilding of the complex seemed to be unlikely in fetal development, especially in the very late stage between 30-40 weeks [10,19].…”

Morphometric properties of the tensor fascia lata muscle in human foetuses

“…Although literature reported a number of differences in many muscle growth dynamics between fetuses [2,4,13,14,17,25], no quantitative studies on TFL were…”