THE EVIDENCE
A FRAMEWORK FOR THE SURF STRONG INJURY PREVENTION TOOL
It is important for Physiotherapists to understand not only which screening assessments to implement but why the literature supports their use for surfers. This section will outline the justification for the use of each component of the screening tool
QUESTIONNAIRE:
Age:
Surfers over the age of 50 are at an increased risk of supraspinatus tear (Dimmick et al., 2018).
Older surfers are more likely to sustain chronic injuries as they are likely to have been surfing for more years, and are less likely to sustain acute injuries as they may not be performing high risk manoeuvres such as aerials as frequently (Furness et al., 2014).
Surfers over 38 years of age are more likely to sustain chronic injuries (Furness, Hing, Walsh, Sheppard & Climstein, 2013).
Surfing stance:
Lower limb injuries predominantly affect the back leg (Hohn et al., 2020) as it is responsible for power and torque. It is therefore useful to know which leg is the surfers back leg.
Surfing frequency:
Higher surfing frequency increases the likelihood of muscle imbalances and asymmetries.
Increased risk factor for acute injury (Furness et al., 2015).
Number of hours surfing per week:
Surfers have an increased likelihood to sustain acute injuries when surfing over 6.5 hours per week (Furness et al., 2015)
Time in sport:
Surfers who have been surfing for a greater period of time are more likely to have increased muscle asymmetries and may also be at a greater risk of developing a chronic injury.
Competitive status/experience level:
1 in 3 recreational surfers are injured over a 12 month period versus 1 in 2 in competitive surfers (Furness et al., 2014).
Competitive history is an increased risk factor for acute injury (Furness et al., 2015).
Experienced surfers are more likely to perform high risk manoeuvres (Furness et al., 2015).
Aerial manoeuvres:
Surfers performing aerials are at an increased likelihood of sustaining ankle and midfoot injuries (Inada et al., 2018).
Surfers completing aerials are at the highest risk of injury (McArthur et al., 2020)
Strength training history and current strength training:
This is important for the Physiotherapist to understand and may help to direct the exercise program developed.
Surfboard length (feet):
Surfers riding a shortboard are at a greater risk of a acute injury particularly to the lower limbs as larger turns and aerial manoeuvres are able to be performed (Inada et al., 2018).
Maximum wave height surfed:
Larger waves will be more consequential if the surfer falls whilst paddling into or riding the wave, increasing the surfers risk of injury.
Predominant wave direction surfed:
Important for Physiotherapist to understand whether the surfer is mainly surfing on their forehand or backhand to best understand the manoeuvres the surfer is performing.
Dominant arm:
Greater strength differences in the rotator cuff muscles have been shown to exist between the surfers dominant and non-dominant arm (Furness, Schram, Cottman-Fields, Solia & Secomb, 2018). This may lead to a greater risk of injury to the weaker/non-dominant arm.
PHYSICAL ASSESSMENT:
General range of movement and strength screening:
Clinical reasoning:
The range of movement and manual muscle testing conducted are extremely important as is the case for many musculoskeletal presentations. The purpose here is different from a typical assessment undertaken by Physiotherapists however as instead of looking for impairments resulting from injury, the Physiotherapist must screen for asymmetries that may be present and are commonly developed as a result of surfing.
It has been suggested that Physiotherapists and strength and conditioning coaches may look to strengthen the opposing muscle groups to those commonly used in surfing. A key example here is to strengthen the external rotators to counterbalance the increased strength often seen in the internal rotators of surfers due to the action of paddling (Furness, Schram, Cottman-Fields, Solia & Secomb, 2018). This will help to reduce asymmetries in unilateral external rotation/internal rotation strength ratio which have shown to be present in shoulder and rotator cuff pathology (Kim, Lim & Kong, 2021). Furthermore, ankle range of motion is an important factor in ankle injuries, particularly for aerialists (surfers performing aerial manoeuvres regularly), thus screening here is important to reduce such injuries (Furness et al., 2015).
Recent studies have also encouraged the use of musculoskeletal screening for muscle weakness, length and range of motion at the shoulder, knee and ankle (Furness et al., 2015), therefore this screening protocol looks to implement this as a method to determine where imbalances may be present, informing the Physiotherapist of their patient’s risk of becoming injured.
Possible impairments:
Decreased Range of Movement.
Decreased strength.
Surfing specific assessments:
Y balance test:
Clinical reasoning:
Both the range of motion and proprioception of the ankle joint are important factors to assess, these limitations increasing a surfer’s risk of ankle injuries, notably lateral ankle sprains. The Y balance test is able to be used as an indicator of ankle proprioception and the function of the ankle can be observed by the Physiotherapist throughout this test (Furness et al., 2015).
The Y balance test has been shown to be a reliable indicator of risk of injury to the lower limb, with factors such as decreased muscular endurance and poor neuromuscular control being key factors contributing to lower scores in individuals (Freeman, Bird & Sheppard, 2013). Thus, it is hypothesised that decreased biomechanical balance ability as shown through the Y balance test may be indicative of surfing injuries (Freeman, Bird & Sheppard, 2013). Specifically, patients with ACL deficiency are also likely to have poor dynamic postural control which can be detected through this test (Freeman, Bird & Sheppard, 2013). The anterior reach is quadriceps dominant, posteromedial and posterolateral reaches rely more so on the gluteus medius, gluteus maximus and rectus femoris (Freeman, Bird & Sheppard, 2013).
Possible impairments:
Anterior reach asymmetries over 4cm between legs may indicate an increased risk of lower limb injury (Freeman, Bird & Sheppard, 2013).
Knee flexion angle of less than 63 degrees are likely to decrease anterior reach score (Lehr et al., 2013).
A combined score of less than 94% may indicate a risk of injury for the lower limb (Plisky et al., 2009).
Decreased scores are indicative for poor neuromuscular control and postural stability (Freeman, Bird & Sheppard, 2013).
Individuals with a posterolateral reach score of less than 80cm were found to be at a 48% increased chance of ankle sprain (Lehr et al., 2013).
Single Leg Squat:
Clinical reasoning:
The single leg squat has been identified through EMG to require strength from the gluteus maximus, gluteus Medius and rectus femoris (Freeman, Bird & Sheppard, 2013). By completing a functional test such as the single leg squat the Physiotherapist can observe the hips, knees and ankle to identify where there may be decreased balance and any other potential factors that may predispose the surfer to injury. This will moreover be important for the surfer’s back leg which is placed under increased load during landing manoeuvres.
Possible impairments:
Dynamic knee valgus
Trendelenburg sign
Flailing arms
Unable to complete test
Hamstring/Quadriceps (H:Q) ratio:
Clinical reasoning:
A low hamstring to quadriceps ratio places the surfer at an increased risk of lower limb injury (Myer et al., 2009).
It has also been found that increased hamstring force during the landing phase helps to decrease the strain placed on the ACL as well as other passive structures around the knee such as the MCL by decreasing the varus/valgus force inflicted on the knee joint due to ground reaction force (Withrow, Huston, Wojtys & Ashton-Miller, 2008).
Possible impairments:
Low hamstrings to quadriceps (H/Q) ratio
The Drop Jump test:
Clinical reasoning:
Turning manoeuvres and aerials involve landing with high forces being placed through the ankle, knee and hip joints. It is very important for the Physiotherapist to observe the surfer landing from a height in a controlled environment. Key aspects to observe will be the range of motion at the ankle, knee and hip and whether a certain leg is being favoured upon impact. The hamstrings to quadriceps ratio should also be considered in conjunction with this test as this is likely where impairments due to decreased hamstring strength will be present, such as failing to achieve at least 30 degrees knee flexion.
Landing mechanics through the drop jump test should be observed bilaterally and also unilaterally as landing from manoeuvres in surfing is often completed with uneven weight distribution between legs due to the unpredictable nature of the wave and the angles the board may land on the wave after aerials (Forsyth, Riddiford‐Harland, Whitting, Sheppard & Steele, 2020). Asking the surfer to land as if they were completing an aerial should also be performed separate from the standardised test and key features such as landing with the centre of mass over the front foot, showing increased and adequate dorsiflexion range of motion should be observed (Forsyth, Riddiford‐Harland, Whitting, Sheppard & Steele, 2020). Decreased dorsiflexion in the leading foot increases the loading forces in the ankle joint and is predictive of lower limb injury, this supporting the importance of knowing the surfers stance and observing their ankle joint in landing (Forsyth, Riddiford‐Harland, Whitting, Sheppard & Steele, 2020).
Furthermore, research suggests it is very important to adequately screen for correct landing mechanics on stable ground, this can then be taught correctly on stable and unstable surfaces to simulate the surfing environment (Furness et al., 2015).
Possible impairments:
Decreased ankle, knee or hip range of motion
Dynamic knee valgus
Ipsiliateral trunk rotation
ER/IR ratio (prone):
Clinical reasoning:
Surfers have been identified to have asymmetries in rotator cuff strength, with the external rotators likely to be significantly weaker than the internal rotators unilaterally (Furness, Schram, Cottman-Fields, Solia & Secomb, 2018). This is likely due to the increased load placed upon the internal rotators throughout paddling. It has also been noted that external rotator strength differed between sides for surfers, with the non-dominant shoulder being weaker (Furness, Schram, Cottman-Fields, Solia & Secomb, 2018).
Moreover, the prone position should be employed for this test as this replicates the surfers paddling position where much of their time in the water is spent (Furness, Schram, Cottman-Fields, Solia & Secomb, 2018). Therefore, the test can be modified in this way to increase its specificity. It is important however that this testing position is standardised across all surfer’s as the external rotators of the shoulder have been shown to be significantly stronger in this prone position (Riemann, Davies, Ludwig & Gardenhour, 2010). If asymmetries are found, it is recommended that strength training is provided to reduce muscular asymmetries and therefore reduce the surfers risk of shoulder injury (Furness, Schram, Cottman-Fields, Solia & Secomb, 2018).
Furthermore, it has been hypothesised that the increased demands on the external rotators may result in chronic fatigue leading to impaired glenohumeral joint translation, ultimately placing the shoulder at increased risk of injury (Weldon & Richardson, 2001).
Strength differences between the internal and external rotators of the shoulder are normal, with a 3/2 ratio expected in individuals. Surfers are at a greater risk of increasing the discrepancies however due to the load placed on the internal rotators when paddling, this acting to increase the surfers’ risk of shoulder pathology. It is recommended that minimising these discrepancies through strengthening to produce a ratio closer to 1 will help to reduce risk of injury in surfers (Furness, Schram, Cottman-Fields, Solia & Secomb, 2018).
Possible impairments:
Reduced external rotator to internal rotator (ER/IR) ratio
Posterior shoulder endurance test:
Clinical reasoning:
There is strong evidence for decreased endurance of the shoulder muscles active in paddling being predictive of shoulder pathology (Bagordo et al., 2020). These muscles are placed under constant load during paddling, which amounts to the majority of a surfing session. Poor endurance leads to increased loading of the shoulder joint, resulting in impaired paddling action which may increase strain on the shoulder joint (Furness, 2015). It is therefore extremely important to identify this in surfers and to build endurance of the posterior shoulder muscles if low endurance is found.
Possible impairments:
Low endurance
Biering-Sorensen (spinal extension endurance) test:
Clinical reasoning:
Maintaining extension of the spine is a very important component in paddling. A failure to hold this position whilst paddling is likely to predispose the shoulder to injury. Specifically, decreased extension will result in the surfer producing increased shoulder flexion and subsequently overloading the supraspinatus tendon (Nathanson, 2013).
Research has also noted the increased likelihood of developing scapula dyskinesis leading to impingement of the shoulder due to decreased thoracic extension, further highlighting the importance of extension endurance for surfers, particularly to reduce the incidence of shoulder injuries (Langenberg et al., 2021).
Furthermore, research from Dimmick et al (2018) encourages targeting core strength and spinal extension endurance to enable a rounder paddling movement with less movement of the elbow to reduce shear forces on the dorsal aspect of the rotator cuff.
Two tests have been identified to be appropriate to assess endurance of the spinal extensors, these being the Biering-Sorensen test and the prone isometric chest raise test. Whilst the prone isometric chest raise test appears to better replicate the paddling position, a meta-analysis of trunk based endurance tests found that this test has not yet been shown to have sufficient evidence to support it's use in the clinical setting, whereas the Biering-Sorensen test is reliable and this study supports it's use the clinical setting (Martínez-Romero et al., 2020).
Possible impairments:
Decreased endurance
Knee to wall test:
Clinical reasoning:
It has been shown that for turns and aerial manoeuvres, surfers require excessive dorsiflexion range of motion, particularly in their lead foot (Forsyth, Riddiford‐Harland, Whitting, Sheppard & Steele, 2020). A decreased dorsiflexion range of motion is furthermore predictive of an increased likelihood of ankle injury with the increased loading of forces at the ankle as a result (Forsyth, Riddiford‐Harland, Whitting, Sheppard & Steele, 2020).
A study of gymnasts also showed that increased dorsiflexion range significantly decreased their risk of injury (Wright & Crée, 1998). Whilst this cannot be directly translated to surfing, the high incidence of injuries due to landing in gymnastics and how this mirrors landing in aerial manoeuvres for surfers therefore justifies its use in this screening tool.
Possible impairments:
Reduced ankle dorsiflexion range of motion