When master Ironman Athletes such as Gordon Ramsay compete, they face a high chance of injury during the running phase of the triathlon, due to the increased stress and extreme fatigue on the muscles from constant use. Collins et al, (1986) highlights this, suggesting 70% of injuries during triathlons occur in the running phase of the race. Additionally, the likelihood of injury for Ramsay is increased  because of the several degenerative musculoskeletal changes that happen to the body due to his age, which may lead to Sarcopenia; the loss of muscle protein mass and muscle function (Rolland et al, 2008). Ramsay has acquired various injuries throughout his athletic career. One of which was in 2014, where he severely tore his Achilles tendon, which was most likely due to the link between Sarcopenia and chronic overuse. Overuse injuries are the most common injury which master athletes endure (Stokell, 2014), and by highlighting specific ways to prevent injuries such as this is crucial into maintaining Ramsay’s fitness.

Why do some older runners need to change their running technique?

With ageing, the ability to run faster declines gradually and the risk of injury increases. This is mainly due to the atrophy of muscle mass with reduction of its cross-sectional area (Frontera et al, 2000), however this is also due to a deficit in force production during the interaction between myosin and actin filaments. Other reasons for a decrease in performance and increase injury frequency is muscle elasticity and altered gait biomechanics (Sterling et al, 2014). Due to a reduction in force production, there is a lower vertical acceleration, a smaller vertical displacement and lower effective aerial time, all of which results in a higher step frequency and a decreased stride length, as shown in Figure 1.

In this study, the older participants had a 6% shorter stride length and a 7% higher stride frequency. Furthermore, Cavanga et al, (2008) states that the cause of the increase in step frequency and decrease in stride length is by a force reduction in relation to degeneration of muscle strength. Duarte et al, (2008) also states in his study that older adults had a greater stride frequency compared to young adults.

Additionally, Cavanga et al, (2007) suggests that the deficit force would result in the lower take off leg causing reduced amplitude of the vertical oscillation, with a reduced elasticity in the muscle. The higher stride frequency results in a less efficient running technique. Cavanga et al, (2008) also suggests that running with high, long leaps is a ‘convenient strategy to decrease the request in oxygen consumption’, therefore Ramsay should attempt to prevent the occurrence of a high stride frequency and reduced stride length when running.

Why do older athletes have a shorter stride length and increased stride frequency?

To explain the higher stride frequency and reduced stride length, figure 2 shows a lack of force generated while running and displays a clear distinction between old and young runners. These results show that older adults generated about 9% less force per stride for a certain running speed compared to younger adults. Theses results also show that older adults have a reduced force generation per meter distance compared to younger athletes, which highlights the need for an increase in force production while running.

Duarte et al, (2008) also found in their study that there was a significant decrease of the range of motion of the tibia at the transverse plane in the stance phase of running in older participants. Arampatzis et al, (2005) suggests that stiffness in the muscles increases in correlation to age. In figure 3, there is a clear distinction between older (O) and young (Y) athletes having stiffer quadriceps femoris, however there is less of a convincing distinction between stiffness in the Triceps surae. Through having stiffer muscles, the frequency of injury increases and may be one of the reasons Ramsay tore his Achilles tendon in 2014 and missed the Ironman later on in the year.

Farley et al, (1996) gives evidence into how the leg stiffness can be reduced using bouncing movements and exercise techniques. By hopping in various speeds and frequencies, the stiffness of the leg can be changed drastically. In addition, bouncing vertically on a flat board can change the stiffness of the leg spring in response to the changes in the knee angle (Greene and McMahon, 1979). Furthermore, by running with an increased knee flexion (Groucho running) the stiffness of the leg decreases (McMahon et al, 1987). Methods such as this can decrease muscle stiffness for older athletes, and in turn, decrease stride frequency and increase stride length (Farley et al 1996), as well as reducing the risk of injury.

Additionally, evidence suggests that decreasing stride frequency and increasing stride length at a given running speed has strong effects on energetic cost (Williams, 1982), impact forces on the musculoskeletal system (Clarke et al, 1983) and the mechanical power of the center of mass and limbs (Cavange et al, (1991), therefore making the running technique more efficient. In 2015, Ramsay did not finish the Ironman in Kona due to severe dehydration. Through making his running technique more energy efficient, the chance of dehydration is reduced.

Biomechanical analysis on running gait

Analysis on the biomechanics of running gait shows subtle differences when comparing young to old athletes. This is due to the different configuration of mechanical output generated by the hip, knee, and ankle joints, which is commonly independent of speed, gender and aerobic capacity. (Beijersbergen et al, 2013). Older adults’ gait is characterised by a distal-to-proximal shift in mechanical output. The hip power increases and ankle power decreases with little or no change in knee joint power. This pattern of redistribution of joint powers is referred to as the age-related biomechanical plasticity of gait (Rider et al, 2016).

 

The consequences of this results in a decline in self selected habitual gait speed, and can result in a reduction of speed by 16% per decade. However, methods to increase the gait speed can be implemented. Takamasa et al, (2014) states that ankle plantar flexors contribute to over 70% to the total leg mechanical output in the propulsion/take off phases of gait, therefore by strengthening the muscles surrounding the ankle (gastrocnemius) even slightly, it will result in a significant role in increasing gait speed. Also, Takamasa et al, (2014) states that older athletes use their hip extensors more and ankle planter flexors less when compared to younger athletes, therefore by increasing hip muscle strength, such as the ilopsoas, gait speed will be increased, resulting in a more efficient running technique.

 

 Muscle stress leads to injury

 

Although running has many physiological health benefits, it is also associated with a high rate of overuse injuries, with a rate of over 79% (Goss, 2012). It is suggested that the most prevalent injury site is the knee, with anterior knee pain reported more often than any other area (van Mechelen, 1992). However, Mckean et al, (2006) suggests older runners are more prone to calf and hamstring injuries, and less prone to knee injuries. There is strong evidence to suggests that because of the degeneration of muscle strength in lower limb muscles, there becomes an increase in muscle stress, therefore more prone to injuries in these areas.

Figure 5 shows peak muscle stresses for the hamstring, soleus, and gastrocnemius for the Young, Old, and Older participants. There is a 4% increase when comparing Young and Older peak stresses in the hamstring, soleus and gastrocnemius. When the peak stress was exerted to their maximum values, there was a decrease of 41%. This evidence suggests that there is more stress in the muscle when the muscle ages, suggesting a need for strengthening specific muscles in the lower limbs to enhance the prevention of injury.

Furthermore, by increasing flexibility it will reduce stress in the muscle (Miller et al, 2012). To increase flexibility, Ramsay should participate in proprioceptive neuromuscular facilitation stretching. This increases the range of motion and decreases tendon stiffness significantly (Konrad et al, 2014).  Duarte et al, (2008) suggests that a reason for the higher strain rates on the musculoskeletal system when running is due to a ‘significantly shorter’ time to peak of rear foot eversion, which has been related to the incidence of running injuries (Messier and Pittala, 1998). Therefore, by landing on the rear of the foot, it will increase the time of rear foot eversion and in turn reducing the strain on the muscle.

What can be done to help running efficiency?

In order for Ramsay to prevent injuries re-occurring, the development of running shoes for older athletes should be worn. However, one main concern for running shoes is to provide movement control for the rear foot and well as shock absorption during the stance phase to decrease excessive pronation, Fukuchi et al, (2014). In addition, due to older runners displaying higher vertical impact speeds, higher impact forces and higher initial loading rates compared to younger runners, it suggested that there is a decrease in the shock-absorbing capacity of the muscular skeletal system, and therefore an increase of the load of bone joint and soft tissue in the lower limbs. This states that to minimise the chance of injury, older runners should wear shoes with optimal cushioning to decrease shock at the initial contact phase of running (Duarte et al, 2014).

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