TRAINING CONSIDERATIONS FOR POST SHOULDER SURGERY RECOVERY

– Written by Ahmed Al-Jawad, Francis Kattoura, And Leopoldo Buttinoni, Qatar

INTRODUCTION

Shoulder rehabilitation post-operatively requires an integration of clinical criteria, applied biomechanics, training principles and sports-specific benchmarks in post-surgery recovery.

There are many factors that need to be considered, such as post-operative restrictions, range of motion, motor control, strengthening, reactive strength, and power/explosiveness. These factors should not be seen as separate entities, rather, all interrelated and complimentary to one another. There are now well-established protocols that exist for the recovery of lower limb injuries relating to these components of rehabilitation. However, the same depth of protocols seems to be lacking for the shoulder. The conversations regarding rehabilitative approaches, progression criteria, quantitative testing and the definition of performance are increasingly dynamic and gaining momentum.

In particular, strength and power complement each other as they are underpinned by the inverse force-velocity relationship, which serves as a foundational framework for designing shoulder rehabilitation protocols and guides the prescription of rehabilitation exercises. Nevertheless, they are both aspects of movement that need to be addressed separately, as power training does not necessarily transfer in strength gain and vice versa. Muscle strength recovery is typically considered a cornerstone milestone for documenting the progression of athletic shoulder rehabilitation and is a prerequisite for the development of power. For instance, baseball pitchers demonstrate 33% slower fastball velocities if shoulder external rotation is weak¹, while in volleyball, attack velocity is significantly correlated with the strength of the internal rotators of the dominant shoulder².

Interpreting strength and power in the shoulder is not straightforward. The role of the shoulder in directing the hand through space requires a type of strength that is not always linear or merely the result of an absolute peak force, as is often the case in the lower limb. Instead, it demands coordinated, fluid, and rhythmic strength which enables multiplanar, articulated movements that more accurately reflect both the anatomy of the glenohumeral joint and the reality of a movement, rather than the mechanical repetition of a linear lift. 

It is within this context that the approach of this article is to present key considerations for the assessment and rehabilitation of strength and power for the post-operative shoulder.  Recognizing that beyond temporal parameters alone, it is essential to guide and document the rehabilitation process using a criteria-based approach in which strength plays a central role³. The article will outline principal rehabilitation strategies employed at Aspetar to optimize patient outcomes. 

POST-OPERATIVE CONSIDERATIONS

Immediate post-operatively considerations for tissue healing must be considered. Although rehabilitation is shifting from time-based to criteria-based progressions, respecting the biological healing timelines following shoulder stabilisation and rotator cuff repair remains essential to protect the surgical outcome and minimise long-term complications. Typically, this is guided by the surgeon’s evaluation of the tissue quality and surgical procedure. The main consideration is the minimal stress on the surgical site to allow for the proliferation of fibroblasts to form a collagenous scarring and alignment. Specifically, to rotator cuff repair, the Sharpey’s fibres that attach tendon to bone become significant in numbers only at 12-weeks. Understanding this concept helps inform our loading approach⁴. In both instances, using clinical reasoning to apply protected range of motion and submaximal isometrics and working different parts of the kinetic chain while respecting irritability is advised^4,5.

DEFINING STRENGTH AND POWER

Strength in rehabilitation is defined as the ability of a muscle group to generate force to overcome or resist an external load.  While strength is the ability to generate force, power is the ability to produce that quickly – which is a critical component of athletes that require explosive movements. Power is defined as the rate at which work is done, more commonly known by its equation of power = force x velocity. In the “Aspetar Way”, we refer to this component of rehabilitation as explosiveness. Strength and power shoulder should not be treated as consecutive steps, although a foundation of strength is required to start explosiveness.  

An inverse force-velocity relationship in muscle contraction exists described well by the force-velocity curve. The faster a muscle contracts, the less force it can generate and vice versa. For example, in a weightlifter deadlifting his maximum weight, the force generation would be high, but the velocity of the lift would be relatively slow. Conversely, a cross fitter doing a box jump would produce a higher velocity with relatively less force compared with the weightlifter. This guides our introduction of both strength and power exercises. Training for absolute strength based on the force-velocity curve means training at speeds slower than 0.5 meters per second, whereas training for peak power has been shown to be most effective at speeds between 0.75-1 metre per second⁶. Applying this principle can help add objective parameters to rehabilitation training sessions after considering any post-operative restrictions. Later in the article this concept will be used to discuss a data-driven, technology dependant training approach.

CLASSIFICATION OF SPORT 

Before delving into the individual components of strength and power, it is important to appreciate that different upper limb athletes require different approaches. It is essential to approach these with an appropriate needs analysis of the sport demand. The Bern Consensus⁷ classifies upper limb sports these into three overlapping categories of: 1) above shoulder height, with or without throwing, 2) below shoulder height with or without throwing 3) reverse chain, all of which could or could not involve collisions. Reverse chain is when the upper limb is in direct contact with the competition surface. For example, this could include contact with the oar in rowing or a gymnasts contact with the rings. The end goal determines the rehabilitation process from the early stages. A thrower’s strengthening and consequently power training will have a heavy focus on above shoulder height strength and power training in comparison to a rowing athlete that spends little to no time in an overhead position.

ASSESSMENT OF STRENGTH AND POWER

Providing objective, data-informed treatment is empowered by the integration of technology. Implementation of quantifiable measurements for strength, symmetry, and performance across many planes of motion can be assessed using several tools including Isokinetic Dynamometry (IKD), Handheld Dynamometry (HHD), externally fixed dynamometry (EFD), and the use of force plates.

IKD is the gold standard for testing shoulder internal and external rotation of the shoulder. It can comprehensively analyse muscle strength, endurance, fatigue, and external rotation (ER)/internal rotation (IR) strength ratios. It is important to recognise the variability in the ER/IR ratio that exists between different athletic populations and activities. This complexity is challenging for practitioners who are tasked with making decisions on athlete readiness for return to sport and performance. An ER/IR ratio of 65-77% has been recommended for a post-operative anterior stabilised shoulder⁸. Moreover, crucial for determining whether one is ready to resume sports is Limb Symmetry Index (LSI), with a target symmetry of at least 90% against the uninjured shoulder⁸. However, it is crucial to acknowledge that pre-injury asymmetry is common especially for overhead throwing athletes. As a result we should consider potential downfalls of solely using this metric to evaluate shoulder strength. In addition to the IKD’s ability to determine peak torque data, it can also produce endurance data. It refers to the capacity of maintaining repeated and prolonged activities or movements while resisting fatigue, which make it crucial in high repetition athletic events, such as throwing⁹. In the absence of IKD, endurance can be clinically measured daily via subjective test, Rate of Perceived Exertion (RPE), Repetitions Maximum (RM), and Set-to-Perceived Exertion Threshold (SET/PSET)¹⁰. Despite being subjective, these consistent tests can help in providing insights on workload tolerance and recovery patterns, guiding as a result the therapist to fine-tune his loading program and avoid overtraining. 

Although not as comprehensive, HHD strength testing can be useful in clinical practice due to its small size, affordability, and ease of set up, compared with other testing devices. Due to its user dependency HHD can be used for both isometric and break tests, where break tests give a true value of the muscle strength capacity¹¹. In comparison to HHD, EFD is a fixed dynamometer that eliminates the human error component. EFD also has its disadvantages compared to the above due to its inability to test the “breaking” force, timely set up and experience dependency with the device. Break tests show the muscle’s resistance to lengthening under stress, while the isometric testing measures the force a muscle can generate in a static position. Both HHD and EFD have shown excellent reliability in different positions¹¹.

Different positions can be utilised for testing such as standing, sitting, supine and prone positions as well as angles of 0° and 90°. Positioning and testing do not seem to have a significant difference on testing result when repeatedly using the same test¹¹. However, testing in different positions can help assess a muscles ability for different functions. The key is that a testing position should be established that best suits the therapist and patient and continually tested in the same position. The two test approaches largely evaluate strength in each movement direction and shoulder moments rather than distinguishing muscles. Therefore, consistency in the choice of testing procedure, direction and angles is essential to guarantee trustworthy tracking of improvement and informed clinical decisions over the rehabilitation period.

The athletic shoulder ASH test may add value in the overhead or athlete’s specific positions. It is assessed using a force plate, with the athlete in prone with a straight arm at varying abduction angles of 90°, 135°, and 180°, otherwise known as the ‘T’, ‘Y’ and ‘I’ positions respectively, depending on the relevance of the sport¹². The advantage of the ASH test over the previously mentioned is it measures the ability of the shoulder to produce force at the outer ranges. Examples of its applicability at the ‘T’ position are a rugby tackle, at the ‘Y’ position a goalkeeper in football reaching to save the ball, and at the ‘I’ position blocking a spike in volleyball.

Assessment of power in the shoulder is a field lacking clarity. There is often discussion among clinicians about the validity and reliability of assessment measures, likely due to the difficulty of standardizing movements that involve both force and velocity measures across different planes. Push up testing in the form of a counter-movement push up (CMPU) and press jump (PJ) has been investigated in the literature. It is performed using force-plates and provides information not limited to peak force, time to peak force, eccentric impulse phase, concentric impulse phase and landing forces. The information generated from this assessment can give insights into if an athlete is avoiding the use of the operated limb or is unable to generate the appropriate forces. A challenge for clinicians is that normative data in the literature is limited and often needs to be interpreted in relation to the sport and to athlete anthropometric features. The research for push up testing is limited to contact and collision athletes¹³.

Despite the best intentions with testing, practitioners need to bear in mind that there are factors that may affect assessment results such as limb dominance, fatigue, test set and time of day in testing. The key difference from the lower limb is that it is unlikely that one testing battery will exist for the upper limb due to the multiple different uses over a variety of sports.

TRAINING PRINCIPLES

Once an athlete is assessed and we have data to drive the rehabilitation, we can apply some training considerations to maximise training sessions. Effective shoulder rehabilitation requires progressive and targeted strengthening. Rehabilitation protocols aim primarily to protect the integrity of repaired or injured tissues, enhance joint stability and restore muscular balance.

As mentioned earlier, there is a biological healing timeframe to respect before initiating maximal loads after shoulder surgery. Progression from passive to active-assisted then active strengthening with isotonic movements, and finally sport-specific drills is commonly implemented. The advancement through these stages should be guided by the patient’s surgery specific recovery timeframe, movement quality, and irritability. Movement quality refers to aberrant or compensatory movements during a given task, therefore knowledge of the biomechanics of the specific sport is required. Whereas irritability is the athlete’s symptom response to certain movements. This includes how easily the symptoms are produces, how severe the symptoms are and how long the symptoms last. These are important when progressing through the following considerations of training of strength and power.
A rehabilitation program for strength and power needs to factor in multiple concepts such as single versus multi- joint movements, open kinetic chain (OKC) versus closed kinetic chain (CKC), short versus long lever, planes of movement, supported versus unsupported movements and mechanical load progression. These considerations should direct our ultimate objectives in rehabilitation and constitute the foundation of functional exercise choice.

Shoulder movements fall under general categories of pushing, pulling, carrying, elevating, and throwing either at below or above shoulder height, which are not isolated, single-joint movements. Single-joint exercises help restore basic control and specific muscle strengthening based on deficits. It eliminates distractions faced when an athlete is re-learning a skill and breaks down a movement for simplicity. Whereas multi-joint patterns applicability to relate to the sport-specific needs.

OKC is when the distal segment of the limb is free to move in space whereas CKC is when it is fixed or in contact with a surface. OKC may be used when the goal of the session is to isolate specific joints and muscles earlier on in the rehabilitation, whereas CKC may be used to encourage joint compression, co-contraction of muscles, promote neuromuscular and proprioceptive feedback and mimic weight bearing and functional tasks.

The range of muscle contraction is also an important consideration. Training in all ranges guarantees that muscles are not only conditioned to produce and absorb force at both inner- and outer- ranges but also to optimally handle loads at mid-range. An important consideration is the applicability to the sports and perhaps the surgical procedure. For example, training in outer range abduction is not recommended following anterior stabilization early in the rehabilitation. However, the same movement may be required to meet the demands of an overhead collision athlete such as a hand ball player but not as relevant for a rowing athlete throughout the rehabilitation journey.

Supported and unsupported movements follow a similar narrative in that a supported movement may be beneficial in the earlier stages or when a deficit resurfaces later in the rehabilitation process. Unsupported movement require more attention, multiple muscle involvement and relate more closely to a sporting environment. The progression from supported to unsupported can be particularly useful when introducing movements above.

Load progression is a pillar of any rehabilitation program. It is important to monitor load to ensure that there are no spikes during training to minimise injury risk and but also to ensure that there is adequate mechanical stress to ensure positive change in the tissues⁵. Recording loads throughout the rehabilitation will guarantee the linear progression of strengthening.

As described, all of the above have their place throughout the process and it is the task of the rehabilitation team to apply these principles during the process and evaluate the effectiveness of each at any given stage.

TRAINING MODES

Training equipment can vary between elastics, cables, and free weights. Elastic bands provide variable resistance that increases with elongation, promoting control, joint stability, and gradual loading. The benefit of elastics over the cables and free weights is the constant force required for a given resistance at a given length despite the speed of the movements. This means that elastics could be a good option when introducing power movements to an athlete.  Cable machines allow for a more consistent resistance through the range of motion due to their pulley system, and they enable versatile movement patterns that closely mimic functional and sport-specific actions. Free weights (like dumbbells, barbells, and medicine balls) provide constant gravitational resistance and require significant joint stabilization, making them ideal for developing strength and motor control in multiple planes. Choosing the appropriate modality depends on the individual’s training goals, stage of recovery, and the need for stability or specificity.

While there are not clear criteria to start power training, there are methods in bridging the gap between strength and power. One such method is simply using the concept of the force-velocity curve and increasing the speed of the movements performed previously for strength. Devices for velocity-based training (VBT) allow monitoring of velocity during movement and ensure training with purpose to constantly challenge athletes to perform actions specific to improving their power in relation to their sport. An easy example using the bench press if thinking of improving the concentric impulse or phase of the push-up testing. A VBT device can be attached to the bar and can measure the velocity of the bar as the athlete moves the weight as hard and fast as they can. If the parameters for power of 0.75-1ms are not met, as the rehabilitator we can add or reduce the weight to specifically target this type of training. In the absence of a VBT device, metrics such as throwing distance, metronomes for keeping a certain speed or any other devices that give external feedback can be used. Setting goals to drive individual sessions has been shown to improve outcomes and the suggested techniques can be a great way to provide in-training and on-going feedback. Exercise done with intent and with targets for the athlete to follow have shown to be far better outcomes than without¹⁴.

Power means different things to different athletes. In an above shoulder throwing sport like baseball, power is releasing the ball with enough velocity to strike the batter out. In a collision sport like rugby, power is the ability to fend or tackle an opposition player. In a reverse chain sport like rowing, power is driving the oar through the water efficiently to make the boat move as fast as possible. Understanding that all upper limb athletes require specialized return to play pathways can help guide build appropriate testing parameters, rehabilitation pathways and ultimately return to performance. When producing a rehabilitation plan for power, it is important to factor the needs of the sport to make the rehabilitation relevant for the athlete.

Despite the best intentions, there may be missing pieces in our rehabilitation. Re-visiting the assessment, taking a step back and sometimes revisiting the earlier foundations of motor control and strength may be important in regaining substantial power. Applying these principles, setting data-driven goals and training with purpose at the end stage of post shoulder surgery may have significant influences of return to play confidence, readiness and possibly reinjury rates.  
 

CONCLUSION

Following surgery, shoulder rehabilitation calls for an all-encompassing approach combining clinical criteria, biomechanics, focused training, and sport-specific principles, while strength and power stand as main pillars.

Successful rehabilitation depends on understanding different joint angles and positions, as well as how various muscles work together in kinetic chains. Exercise programs are initiated with basic single-joint motions towards functional multi-joint activities considering progressive loading. Comprehensive strength and power readiness are ensured by specific attention to exercise posture relative to shoulder height, change from closed-chain to open-chain activities, and short-lever to long-lever exercises.

Strength and power streams are guided by the inverse force-velocity relationship. Though each requires focused interventions, strength offers the foundation upon which power training is built. Implementing the force-velocity concept in strength and power streams helps to precisely prescribe loads, monitor progression, safely transition between phases, and improve rehabilitation results.

On the other hand, using objective assessment tools like handheld dynamometers (HHD), isokinetic dynamometers (IKD), force plates, and velocity-based training (VBT) tools provides valuable and consistent data. This information is essential for tailoring rehabilitation programs, ensuring that athletes can recover safely and perform at their best.

However, despite our efforts, there are still significant gaps in our clinical practice. For instance, the absence of standardized power assessments for the upper limb poses a challenge for creating universal protocols. Future research should focus on developing validated tools and understanding how different training affects various athletic populations. Only by addressing these issues can rehabilitation practices evolve to meet the complex needs of modern sports medicine.

 Ahmed Al-Jawad

Physiotherapist

Francis Kattoura

Physiotherapist

Leopoldo Buttinoni

Physiotherapist

Aspetar Orthopaedic and Sports Medicine Hospital

​Doha, Qatar

Contact: ahmed.aljawad@aspetar.com

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