Sonographic landmarks in hamstring muscles

Abstract

The ultrasound examination of hamstrings inspires respect due to the connective complexity of their structures, particularly for sonographers who are not used to this kind of study. Therefore, it is important to know the specific ultrasound reference points that facilitate the location of the hamstring structures, dividing them into four areas of interest: (a) tendinous origin of the hamstring, (b) the proximal half, (c) distal and medial half, and (d) distal and lateral half. The origin of the hamstrings is found at the level of the ischial tuberosity. Here, the connective structures under study are the common tendon and the semimembranosus tendon, together with the muscle fibers more proximal to the semitendinosus, which can also be assessed through ultrasound locating the ischial tuberosity. The proximal half of the thigh consists of a characteristic structure made up by the common tendon, the sciatic nerve and the semimembranosus tendon, enabling to define the biceps femoris and the semitendinosus, respectively. To identify the distal and medial section, the volumetric relationship between the ST and SM muscle masses is used, where it is also possible to identify the three muscles in the knee that make up the pes anserine. To identify the distal and lateral sections, the sciatic nerve pathway is followed until identifying both heads of the biceps femoris. These four areas of interest, with their specific landmarks, show a tuning fork that enables the comprehensive study of hamstrings through ultrasound.

Keywords: Hamstring muscles; Sonoanatomy; Sonographic study; Tuning fork; Ultrasound.

Conflict of interest statement

The authors declare that they have no conflicts of interest.

Figures

Fig. 1

Diagram of the hamstring muscles. BF biceps femoris muscle, ST semitendinosus muscle, SM semimembranosus muscle, CT common tendon, CT(ft) free-tendon part of the common tendon. SN sciatic nerve, IT ischial tuberosity, FH fibular head, FT fat tissue in the space between the BF and ST/SM muscles, (*) Popliteal vessels and nerve are interposed between the BF and ST/SM muscles

Fig. 2

Diagram of expanded hamstring muscles. BFlh long head of the biceps femoris muscle, BFsh short head of the biceps femoris muscle, ST semitendinosus muscle, SM semimembranosus muscle, SMT semimembranosus tendon, CT common tendon, CT(ft) free-tendon part of the common tendon. The dotted line on the femoral diaphysis marks the linea aspera, the origin of the BFsh. IT ischial tuberosity, T medial side of the tibia, BFt distal BF tendon

Fig. 3

The hamstrings form an inverted tuning fork with four areas of study: the handle, the curve, and two arms. Each of these areas contains interesting anatomical structures and specific ultrasound landmarks that facilitate a systematic study of the hamstrings. BFlh long head of the biceps femoris muscle, BFsh short head of the biceps femoris muscle, ST semitendinosus muscle, SM semimembranosus muscle, SMT semimembranosus tendon

Fig. 4

Series of short-axis ultrasound scans showing different views of the proximal part of the hamstrings (handle of the tuning fork). As the probe is moved in a proximal direction, the sections of the common tendon and the semimembranosus tendon can be seen approaching the sciatic nerve until a hyperechoic line is observed with a posterior acoustic shadow consistent with the ischial tuberosity. BFlh long head of the biceps femoris, ST semitendinosus muscle, AM adductor magnus muscle, SMT semimembranosus tendon, CT common tendon, CT (ft) free-tendon part of the common tendon, (*) sciatic nerve. The photographs on the left of the figure indicate probe positioning

Fig. 5

Short-axis ultrasound view of the proximal-mid third of the back thigh with comparative diagram. The section of the sciatic nerve can be seen like the main landmark (remember the iconic Mercedes Benz logo). BF biceps femoris muscle, ST semitendinosus muscle, AM adductor magnus muscle, CT common tendon, SMMb semimembranosus membrane, SMT semimembranosus tendon. The photograph on the left of the figure indicates probe positioning

Fig. 6

a Short-axis ultrasound view of the proximal third of the back thigh. b By placing the probe in the long axis over the sciatic nerve, the biceps femoris muscle can be located. c By placing the probe in the long axis over the semimembranosus tendon (C), the semitendinosus muscle with its raphe can be located. The adductor magnus is located ventral to these structures. BF biceps femoris muscle, ST semitendinosus muscle, AM adductor magnus muscle, White arrows raphe of the semitendinosus. The photograph in the top left of the figure indicates probe positioning

Fig. 7

Series of short-axis ultrasound scans showing different views of the medial part of the hamstrings (medial arm of the tuning fork). As the probe is moved distally, the SM muscle mass can be seen to increase in size, while that of the ST decreases. The photographs on the left of the figure indicate probe positioning. (ST semitendinosus muscle, SM semimembranosus muscle AM: aductor magnus muscle)

Fig. 8

Panoramic ultrasound view of the distal section of the back thigh showing the pes anserine muscles that, from ventral to dorsal, correspond to the semitendinosus (ST), gracilis (G), and sartorius (S) muscles. The entire muscle area between G and ST is consistent with the large muscle mass of the semimembranosus (SM). VM vastus medialis muscle. The photograph on the left of the figure indicates probe positioning

Fig. 9

Series of short-axis ultrasound scans showing different views of the lateral part of the hamstrings (lateral arm of the tuning fork). As the probe is moved distally along the sciatic nerve pathway, the section of the short head of the biceps femoris muscle can be seen to appear. The photographs on the left of the figure indicate probe positioning. BFlh long head of the biceps femoris, BFsh short head of the biceps femoris, ST semitendinosus muscle, (*) sciatic nerve