Muscle Length of the Hamstrings Using Ultrasonography Versus Musculoskeletal Modelling.

Eleftherios Kellis,Athanasios Ellinoudis,Athina Konstantinidou

doi:10.3390/jfmk6010026

Eleftherios Kellis, Athanasios Ellinoudis + Show 1 more

Open Access

https://doi.org/10.3390/jfmk6010026

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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.

Highlights

Hamstring muscle injuries are frequent in sport and they can have a serious impact on an athlete’s performance and career [1]
All methods applied in this study indicated that the SM LMTU displayed the highest relative change compared with biceps femoris long head (BFlh) and ST (Figure 4)
The results of this study indicate that modelling the hamstrings by applying regression equations in combination with joint angle data provide standardised and greater changes in length compared with US-based techniques

Summary

Introduction

Hamstring muscle injuries are frequent in sport and they can have a serious impact on an athlete’s performance and career [1]. The hamstring muscle group includes the semimembranosus (SM), the semitendinosus (ST), and the long head of the biceps femoris (BFlh) These muscles act as hip extensors and knee flexors, research has clearly indicated that there are various differences in anatomy and architecture between them [5,6,7]. Cadaveric studies have shown that ST has a greater muscle-tendon unit length than SM and BFlh [8,9,10,11,12] This may indicate that for the same change in knee and hip position, each hamstring component may display a different change in length. Improvement of the methods used to estimate hamstrings LMTU may assist in a better understanding of the mechanical properties of this particular muscle group

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