Muscle Length of the Hamstrings Using Ultrasonography Versus Musculoskeletal Modelling

Abstract

Muscle morphology is an important contributor to hamstring muscle injury and malfunction. The aim of this study was to examine if hamstring muscle-tendon lengths differ between various measurement methods as well as if passive length changes differ between individual hamstrings. The lengths of biceps femoris long head (BFlh), semimembranosus (SM), and semitendinosus (ST) of 12 healthy males were determined using three methods: Firstly, by identifying the muscle attachments using ultrasound (US) and then measuring the distance on the skin using a flexible ultrasound tape (TAPE-US). Secondly, by scanning each muscle using extended-field-of view US (EFOV-US) and, thirdly, by estimating length using modelling equations (MODEL). Measurements were performed with the participant relaxed at six combinations of hip (0°, 90°) and knee (0°, 45°, and 90°) flexion angles. The MODEL method showed greater BFlh and SM lengths as well as changes in length than US methods. EFOV-US showed greater ST and SM lengths than TAPE-US (p < 0.05). SM length change across all joint positions was greater than BFlh and ST (p < 0.05). Hamstring length predicted using regression equations is greater compared with those measured using US-based methods. The EFOV-US method yielded greater ST and SM length than the TAPE-US method. SM showed the highest change in length at different hip and knee joint positions.

Hamstring muscle activation strategies during eccentric contractions are related to the distribution of muscle damage

“…Semitendinosus: ST; Hams: Hamstring we found the index of increase in shear modulus was larger in ST (10.2%) compared to BF (2.9%, p = 0.035) and SM (−4.9%, p < 0.001). This may be because hamstring heads act at a similar relative length during knee flexion, 38 leading to similar changes in shear modulus for a given amount of damage. For sake of clarity, we have chosen to report the relative changes in shear modulus to compare the distribution of damage among hamstring heads.…”

Neuromuscular characteristics of agonists and antagonists during maximal eccentric knee flexion in soccer players with a history of hamstring muscle injuries

“…Reliability and validity of this dynamometer for isokinetic concentric knee flexion and procedure are described elsewhere [ 16 , 22 ]. Subjects were seated in a rigid chair and firmly strapped at the hip, the torso and distal thigh at 90° [ 23 ]. The rotational axis of the dynamometer was aligned to the lateral femoral epicondyle, and the lower leg was attached to the dynamometer lever arm above the medial malleolus, with no fixation of the ankle joint.…”

“…The index is the time (ms) between onset until the peak torque has been reached. Peak torques were further extracted for the time intervals 0–50 ms, 50–100 ms and 100–200 ms after onset [ 9 ] and for the interval 20° - 0° knee extension (full extension, the BF muscle tendon unit and fascicles are most elongated) [ 23 , 26 ]. Rate of torque development (RTD, Nm/s) was measured as the slope of the MVC torque-time-curve in the time intervals 0–50 ms, 0–100 ms and 0–200 ms [ 22 , 27 , 28 ].…”

Finding consensus for hamstring surgery in ambulatory children with cerebral palsy using the Delphi method

“…45,46 The literature on hamstring architecture and function is developing rapidly and is not yet settled. [52][53][54] We readily concede that neither the theoretical nor clinical basis for HST has a high level of evidence in the Additional basic science studies including musculoskeletal modeling are required. More importantly, randomized trials to compare HST to HSL are required to improve the level of evidence.…”