Essay On Hamstring Injury

Describe the pathology/condition from a reputable source. Include its etiology (how, when and why it occurs)

A hamstring strain is a very common injury that can affect up to three muscles of the posterior compartment of the thigh (Bahr & Engebresten, 2009). It occurs in sports that require maximal speed, force and acceleration, as well as in sports that require sudden changes in movement or direction (Bahr & Engebresten, 2009). This injury can be classified into different grades, depending on the severity, type of action being performed (Duhig, 2017), individual factors and clinical diagnosis of the area. Referring to table 1, A grade one hamstring strain represents no structural damage and insignificant bleeding. A grade two strain results in an incomplete tear with moderate loss of strength and function (Duhig, 2017), whilst a grade three strain causes a complete rupture or tear to the musculotendinous unit (Drez, Bach & Nofsinger, 2008).

During the swing phase of running when the foot contacts the ground, the hamstrings are contracting eccentrically to slow down the extension of the knee and flexion of the hips. This is when a hamstring strain is most likely to occur because the hamstrings are at their greatest length and activation. Thus, when the hamstrings are stretched beyond

normal range, it can cause damage to nearby muscles in the posterior thigh (Bahr & Engebresten, 2009).
There are many factors that can contribute to the sudden onset of this injury. This can include an insufficient warm up prior to the commencement of the sporting activity, muscular fatigue and associated strength issues, cross-pelvic posture, inflexibility and poor rhythmic stride (Kaeding & Borchers, 2014).
Whilst there is still further research required to investigate the roles of these modifiable factors, evidence conducted by Hawkins and Fuller suggest that muscular fatigue can be a contributing factor to hamstring strains experienced by soccer players. Their research identifies that there were more cases of this injury presented towards the end of the first half, as well as in the second half of the match (Bahr & Engebresten, 2009). This can be a consequence of the muscle being able to absorb less force and resisting overstretching (Opar, Williams & Shield, 2012). Additionally, muscular fatigue can increase knee extension during the swing phase, which can lead to a greater likelihood of the hamstrings lengthening beyond normal capacities (Opar, Williams & Shield, 2012).
Research also indicates that a decrease in hip extension range of motion can lead to hamstring related injuries. In Freckleton and Pizarri’s paper (2012), they found that when the hip flexor length was slightly decreased, the risk of the injury was up to 15% more likely for players 25 years and over.

Describe in detail and using appropriate anatomical language the relevant anatomy/physiology of the pathology/condition.
As seen in figure 1, the hamstring is made up of the biceps femoris (lateral), semitendinosus (medial), and semimembranosus (medial) muscles that form part of the posterior thigh (Bahr & Engebresten, 2009). The main action of this muscle group is to flex the leg and extend the hip and thigh. (Moini, 2015). The biceps femoris originates from the ischial tuberosity and posterior side of the femur. The semimembranosus and semitendinosus both originate from the ischial tuberosity and insert on the tibia (Moini, 2015). All three muscles are innervated by the sciatic nerve and more specifically, the tibial division. The short head of the biceps femoris however is supplied by the peroneal branch (Kaeding & Borchers, 2014). Research has suggested that because the biceps femoris is supplied by two different nerve branches, it may contribute to hamstring strains because of the uncoordinated movement that can occur between the short and long heads of this muscle group (Kaeding & Borchers, 2014).
A hamstring strain results in a partial or complete tear to the muscle fibres, as referred to as either grade 1, 2 or 3 clinical grades. The injury is more commonly located in the biceps femoris, however other sites can be affected depending on the type of activity being undertaken (Bahr, Engebretsen & Bolic, 2012). For instance, sporting activities that require speed and maximal effort such as football, will most likely affect the tendon, tissues and muscle fibres that surround the long head of the biceps femoris. Additionally, activities that involve stretching or slow movements such as in some forms of ballet will most commonly affect the proximal free tendon or muscle tendon junction of the semimembranosus muscle (Askling, Tengvar, Saartok, & Thorstensson, 2007). All three muscle groups however can be impacted by a hamstring strain.

Explain the likely presentation of a person with this pathology/condition, and the common signs and symptoms they may be experiencing
Depending on the severity of the injury, a person who has experienced a hamstring strain is likely to grab the thigh posteriorly because of feeling a sudden and sharp pain in this area. Some people may also hear a pop or experience feelings of tightness (Kaeding & Borchers, 2014). Most people who experience this sensation characterise it as being hit or ‘shot’ to the back of the leg (Bahr, Engebretsen & Bolic, 2012). Consequently, when this occurs during accelerated movements, most people will need to immediately stop because of the resulting pain, lack of strength and inability to perform at maximal capacity.

When a hamstring strain is presented to a medical professional, pain, tenderness and resistance to knee flexion are common signs of incurring a strain (Bahr, Engebretsen & Bolic, 2012). Moreover, as can be seen in figure 2, ecchymosis or swelling may be evident at the back of the thigh due the haemorrhage under the skin, or a palpable mass may be felt in severe instances because of a torn tendon or muscle (Bahr, Engebretsen & Bolic, 2012). A straight leg test can be performed to help determine the severity of the condition. Pain or tenderness that can be seen when the leg is raised at approximately 70 degrees towards the body can be a sign (Drez, Bach & Nofsinger, 2008). Medical professionals are likely to clinically diagnose a hamstring strain based on these signs and symptoms, however, medical technologies such as an MRI, ultrasound and CT scans may be used (Kaeding & Borchers, 2014).

Outline the demographic, sporting or occupational group who are likely to have this condition
Hamstring strains commonly occur in sports such as rugby, football, soccer, basketball and athletics because they require maximum speed and rapid movements. Additionaly, this injury can occur in sports such as dancing because the muscle fibres are continually stretched (Bahr & Engebresten, 2009).

As can be seen in figure 3, each AFL club experienced approximately seven hamstring injuries in 2009.

This rate was significantly higher than other injuries such as groin or quadricep strains. This highlights the high incidence rate and concerns surrounding the hamstring strain within the AFL sporting code (Opar, Williams & Shield, 2012). Furthermore, research also acknowledges that a hamstring strain accounts for approximately 26% of all injuries for track and field events, as well as 12 – 14% of all injuries for soccer players. These figures further support the idea that hamstring strains are largely associated with sports that rely on fast movements (Opar, Williams & Shield,

2012).

The demographic groups that are likely to have this condition are older population groups, those who have had a history of hamstring injuries and those with an African or Aboriginal and Torres Strait Islander background (Kaeding & Borchers, 2014). Those who are older are more likely to incur a hamstring injury because of factors associated with a higher body weight, poor flexibility and range of motion, muscular fatigue and a reduction in fast twitch muscle fibres (Duhig, 2017). One paper recognised that AFL players over 25 were four times more likely to incur this injury compared to someone younger than 20 (Duhig, 2017). Furthermore, having a previous hamstring injury significantly increases the susceptibility of incurring another one due to the shift in muscle properties that follows (Bahr & Engebresten, 2009). For AFL players, it has been shown that this risk can be increased between 2.1 – 6.3 times, and alternatively for soccer players, the risk can increase between 3.5 – 11.6 times (Bahr & Engebresten, 2009). Ethnicity has been another factor that can be attributed to hamstring strains. One reason that can account for this is the higher percentage of fast twitch fibres that are responsible for rapid and explosive movements (Bahr & Engebresten, 2009).

Describe the possible treatment or rehabilitation options that are relevant for this pathology/condition
A person’s treatment and rehabilitation for a hamstring strain is important to ensure the best possible outcome. It does however greatly depend on the severity, location and sporting level of the individual as it can take up to 2-3 months to recover (Bahr, Engebretsen & Bolic, 2012). Firstly, the injured person should perform the following sequences: rest, ice, compression and elevation (Opar, Williams & Shield, 2012). Applying ice and compression to the affected area within the first 24 hours can assist in reducing any swelling and bleeding, as well as help with pain management. Protected weight bearing exercises that increase range of motion should be gradually introduced, followed by strength related exercises that build upon the muscle (Kaeding & Borchers, 2014). Before someone can take part in normal activities, it is essential to regain flexibility and strength within the hamstring. Within the later stages of rehabilitation, greater strength and running related exercises should mimic similar training conditions to allow the injured person to build up to a full range of motion (Drez, Bach & Nofsinger, 2008). One method that has been shown to help with this is the Nordic hamstring exercise as it targets eccentric conditioning. This is an important element that can reduce further incidences of hamstring strains (Bourne, Opar, Williams, Najjar & Shield, 2015).

Describe how this pathology may influence movement patterns, and how that may influence future sporting participation
A hamstring strain may cause an individual to miss out on 1 – 12 weeks of sport, depending on the severity of the injury. In the initial phase, the injury will greatly influence a person’s movement patterns as they will be required to rest until the pain, swelling and bruising subsides. This means that any participation in sport is ceased (Bahr, Engebretsen & Bolic, 2012). Next, the strain will result in a reduced function, endurance and flexibility of the muscle, so an introduction to functional and isokinetic exercises will be required to improve movement patterns (Drez, Bach & Nofsinger, 2008). After this, a return to normal sporting activities is very probable as the individual is most likely able to participate without pain, tenderness or restrictedness in surrounding muscles.
Once someone has incurred a hamstring strain for the first time, it will have a great influence on future sporting participation. This is because they are at greater risk of experiencing another one due to the damage and scarring that occurs as a result (Bahr & Engebresten, 2009). It is important for people who have a hamstring strain to manage and rehabilitate the condition appropriately, as well as ensure that they don’t resume activities too quickly. The recurrence of hamstring strains within football codes are between 10 – 40% (Bahr, Engebretsen & Bolic, 2012Without the right measures, muscular fatigue is probable and the risk of experiencing another strain is even greater. This can cause even further time out of the sport which thereby affects future participation.