Semitendinosus muscle architecture during maximum isometric contractions in individuals with anterior cruciate ligament reconstruction and controls

Abstract

SummaryBackground: The most widely used graft as a replacement in anterior cruciate ligament (ACL) reconstruction is the semitendinosus (ST) tendon graft. After harvesting for ACL reconstruction, the hamstring tendon regenerates in most people and becomes similar to normal. The effect of graft harvest on muscle morphology and function remains unclear. The present study aimed to examine the morphology of the ST during isometric contraction after harvesting the ST tendon for ACL reconstruction. Methods: Maximal isometric contractions of the knee flexors from two angular positions were performed by 8 participants, at least 1 year after ACL reconstruction with an ST tendon graft and 8 matched controls. Ultrasonographic images were used to measure the pennation angle and muscle thickness of the ST muscle. Results: There was not a statistically significant difference in pennation angle values between the control group and the group who underwent ACL reconstruction (p >0.05). Muscle thickness was significantly higher in the ACLR group compared with controls (p< 0.05). Conclusions: Individuals who underwent ACL reconstruction display a higher ST muscle thickness but similar pennation angle compared with controls. This indicates that ACL reconstruction has an effect on ST muscle belly but effect on force generation capacity is rather limited. Level of evidence: IIb.

A diffusion tensor-based method facilitating volumetric assessment of fiber orientations in skeletal muscle

“…The measurement of the pennation angle in the BFL and the ST muscles are in line with previous ultrasound studies that reported a pennation angle of 20.74° ± 2.53° as average of N = 8 locations in the BFL muscle [ 36 ] and 18.07° in the ST muscle for control subjects at rest [ 34 ].…”

“…Key to our method is that we defined the fiber angle in 3D and with respect to a reference line. This approach differs from the definition of 2D pennation angle which is the acute angle between the fascicles and the muscle aponeurosis or tendon [ 34 ]. The reference line is determined using two points, which are systematically defined on the basis of well visible anatomical landmarks, such as bones and tendons.…”

The Association Between Strength, Balance and Physical Function with the Body Mass Index in Dyslipidemia

“…As the knee mainly uses concentric contractions during daily activities, the concentric mode was used for the isokinetic tests [22]. The isometric muscle strength test was performed at a 45 o knee extension at a maximal effort of 5 [23]; the isokinetic muscle strength test was applied to the dominant leg at 60 o /second (5 repetition) and 240 o /second (15 repetition) angular velocities at a 0 o extension and 90 o flexion range of joint motion [24,25].…”

Operative treatment for the painful posterior thigh after hamstring autograft harvesting

“…Based on the recent systematic review by Suijkerbuijk et al, the regeneration of hamstring neotendon remains unclear 13 . Although the ACLR done with hamstring autograft is a common procedure, and the muscle morphology of ST seems to recover after the harvesting 14 , the failed regeneration of neotendon during rehabilitation is poorly recognized. Our case examples exhibit early phase postoperative hamstring pain, in which the regeneration process of the neotendon was disturbed during the rehabilitation of ACLR by an early traumatic injury or too early started hamstring rehabilitation, thus impairing the regeneration process of the neotendon.…”