The modifiable intrinsic risk factors are often related with biomechanical and structural deficits, which can be addressed in order to reduce the predisposition to the specific injury. Thus, many modifiable intrinsic risk factors can be taken into account: muscle imbalances or insufficiency [21, 23, 31–34], poor muscle flexibility [23, 34, 35], anatomical malalignments [21, 23], abnormal kinematics [22, 23, 32, 36–41], medication intake [42] and adiposity/elevated body mass index [23, 34, 43–45].

The most important non-modifiable intrinsic risk factor is the occurrence of previous tendon injury at the specific tendon. In addition, other non-modifiable intrinsic risk factors can be pointed out: gender [42, 44, 46–49], increasing age [23, 50–52], blood type O [53, 54], individual genetic predisposition [55–58], anthropometrical variations [31, 34, 44] and hypertension [42].

During maximal effort football kick, the adductor longus seems to be at greater risk of injury in the swing phase, where eccentric active forces and stretching forces occur simultaneously [65–67]. Hence, by decreasing the demand on the adductor longus, it can reduce the risk of injury during cutting or other lateral change-of-direction manoeuvers [68]. Other factors seem to put the adductor tendon at risk of injury:

The scientific literature has few reports regarding the proximal hamstrings tendon pathology, also known as “high hamstring tendinopathy”, “hamstring syndrome”, “ischiatic intersection syndrome”, “hamstring enthesopathy” and “hamstring origin tendinopathy” [73–76]. It is often overlooked as a cause of chronic gluteal pain and includes tendon degeneration, partial tearing and peritendinous inflammatory reaction [15, 76]. Usually, these conditions present subacute onset of deep buttock and/or thigh pain, particularly at the ischial tuberosity, which can be exacerbated by repetitive activity and often is aggravated by sitting [10–13]. Little information is available about the risk factors for hamstrings proximal tendinopathy. In this sense, different possible risk factors can be pointed out:

Patellar tendinopathy seems to be consequent of a combination of different risk factors [22, 43]. Furthermore, it has been suggested that unilateral and bilateral patellar tendinopathies have a unique aetiology [31]. In this sense, the scientific literature has been suggesting different risk factors that may predispose the development of patellar tendinopathy:

Achilles tendinopathy often occurs in athletes who systematically perform running and jumping as sportive actions, including the football [78]. Nevertheless, it specific cause still remains unclear [79]. Some authors have suggested a failed healing response as a major cause for the aetiology of Achilles tendinopathy [80, 81]. In this sense, many risk factors have been suggested to predispose to Achilles tendinopathy:

It has been shown that athletes with tendinopathies related to an overused repetitive sportive gesture, such as jumping in the case of patellar tendinopathy, have also higher performance levels in this specific tasks (e.g. athletes with patellar tendinopathy often show better jumping performance than athletes without patellar tendinopathy) [45, 87]. Nevertheless, these motor control deficits should be properly approached because athletes with tendinopathy at a specific site have potentially increased risk of developing tendinopathy at other locations [88]. Furthermore, it has been shown that tendinopathy-associated motor and sensory (greater cortical inhibition [89]) impairments are often present bilaterally, even when the tendinopathy is presented unilaterally [90]. In addition, once most of lower limb activities are performed bilaterally and symmetrically, the uninjured side may be striving in order to protect the potential vulnerable tendon and stand the loads imposed by the athlete in demand for optional performance [88]. In this sense, the importance of the core and trunk muscles should not be overlooked, since these muscle play an important role in achieving the proper biomechanics and motor control and, therefore, should be included in the prevention program [91]. All these above-mentioned considerations highlight the multifactorial nature of tendinopathy and stress the importance of correctly addressing and controlling the predisposing risk factors.

To design a particular prevention protocol, the clinician should take into account the location of the injured tendon as also the associated deficits. In this sense, addressing the associated strength kinematic abnormalities may play a crucial role in increasing the movement variability, reduce the risk of overuse tendon injury and, in addition, even improve the sports-specific gesture. Along this line, athletes with patellar tendinopathy often show altered landing patterns [92] as consequence of the protective strategies employed to avoid pain [88]. By increasing the movement variability in these athletes will fine-tune the load patterns and decrease the imposed load accumulation in the specific region of the tendon and consequently prevent the potential development of an overuse injury [92–94].

Another essential concept that needs to be properly understood and incorporated into the prevention planning rationale is the tendon biology. It is known that after maturation, tendons undergo biochemical, cellular, mechanical and pathological changes, leading to structural and functional deficits, diminished capacity to readapt to the environmental stress and loss of tissue homeostasis [52]. Moreover, the different tendons have also dissimilar biological characteristics, reflecting into different histopathological, pathomechanical and pathophysiological responses [23, 81, 95, 96]. In addition, within the tendinopathy umbrella, several terminologies can be used (tendinosis, tenosynovitis, paratenonitis), and, therefore, knowledge of these different terminologies is important to better address the preventive programs [23]. Along these lines, neuroplastic training has been proposed as a potential approach for the optimisation of the motor control and sensory neuroplasticity in athletes with tendinopathy [88].

Taking into account all the considerations exposed above, the clinician should be capable to plan a prevention program which includes all these features. Addressing predominantly the motor control and strength deficits, as well as several external factors (in particular, footwear and dietary modification), may determine the success of the preventive program. In this sense, these preventive features should be adapted and directed to the specific tendinopathy to further enhance its effectiveness. A suggested approach to the modifiable risk factors of the different lower limb tendinopathies (adductor, hamstrings, patellar or Achilles) is presented in Table 38.1.

Tendinopathy is caused by multiple factors and therefore should be address by a multidisciplinary team. In this sense, the medical team should work together to prevent and/or modify the different potential predisposing risk factors. Thus, the medical team should include all the sports medicine professionals that may play a role in the different aspects within the sports injury scope: sports medicine physician, physiotherapist, strength and conditioning trainer, radiologist, psychologist and nutritionist, among others.

In addition to the multidisciplinary approach, the prevention program should be customised to the specific tendinopathy and to the football player himself in order to address the different particularities inherent to each individual. Along this line, it is of upmost importance to adapt the prevention program in accordance to the player’s current fitness status, level of competition and positional role in order to enhance the adherence and effectiveness of the program. Moreover, since female football has been fast growing worldwide (nearly 10% of total number of footballers), it is crucial to also know the specificities of the female player, such as hormonal particularities, sexual maturation and anthropometry [97]. In addition, it has been shown that female footballers have different football-specific biomechanical and skills performance [98–102], highlighting the need to adapt the training loads and intensities to their physical demands and capacities [97].

A progression-based prevention program can help the players, once they start with easier exercises and progress to more complex ones as they improve the physical capabilities and skills. Training tips and pearls are described in Table 38.2.

Another important training particularities are the method of strengthening and the loads applied. In this sense, performing muscular assessment allows to tailor the prevention program to fit the needs of each individual athlete. At earlier stages more isometric exercises should be performed in order to initiate the muscle-tendon unit loading, and, as the program progresses, more isotonic exercises can be performed in order to increase the tolerance to higher loads, especially during eccentric exercises. Attention should be paid to excessive loads once these often lead to maladaptations within the tendon structure causing pain [103]. As the strength performance is balanced, high velocity exercises (such as jumping and landing, acceleration, deceleration and cutting/change-of-direction activities) may be incorporated to program aiming to replicate the high demands of football. In addition, exercises targeting motor control and football-specific skills should be implemented into the prevention program.

The tendinopathy in the athlete is usually characterised by pain and impaired performance [104]. Nevertheless, when the symptomatology appears, the inflammation already may be present for a long time, as result of the repetitive loading placed in the tendon [105]. In addition, these injuries often result in prolonged periods of rehabilitation, leading to a delayed return to play [106]. Moreover, biomechanical and strength deficits may persist even after the player return to the competition [88]. Thus, continuous assessment follow-up plays a crucial role in keeping the player healthy and injury-free, ensuring his safe and best performance.