Individual goals must be set for each athlete dependent upon his or her current functional level, the level of competition to which they are to return, and the specific sport of the athlete. In general, the goals of the training program are to restore and/or improve flexibility, endurance, strength, balance, and agility. Once the athlete has completed his or her acute phase rehabilitation, the concept of a needs analysis may assist in establishing more sports-specific goals. The needs analysis takes into account the fitness needs of both the activity/sport and the individual athlete, thus designing a more customized versus a “cook book” program. To develop a needs analysis, both a physiologic and biomechanical analysis must be completed. When considering a specific event, one must look at the muscles involved, the energy system needs, speed/strength/power/endurance requirements, and any other specific needs of the event itself.6 Next, the current status and prior history of the athlete is determined and a program is then designed to progress him or her toward those specific goals. Sport-specific training is fundamental in returning the athlete back to his or her respective sport. The rehabilitation program should incorporate a whole body approach including core strengthening and exercises for the noninjured extremity.

Controversy exists in the literature regarding static stretching.7 Several studies have shown that there is little evidence to support its role in injury prevention and determined that preexercise static stretching may actually negatively affect performance.⁸ Some researchers found decreases in muscle strength⁹ and decreases in jumping ability¹⁰ after passive stretching. The concept of using a dynamic warm-up instead of static stretching has gained popularity in both the literature and on the field. Some of the proposed benefits of a dynamic warm-up versus static stretching are that the muscles are in more continuous movement, thus increasing the overall temperature and achieving a more “true warm-up.” Dynamic stretching can also use more sports-specific movements to incorporate balance and motor control and mental preparation for the athlete, which may help to prime the neuromuscular system for the upcoming event.¹¹ A few examples of dynamic warm-up exercises are heel/toe walking, marching, skipping, long leg kicks, gluteal kicks, lunge walking, carioca, and lateral slides. This does not mean that static stretching should be abandoned, however. Shrier⁸ contends that regular stretching as part of a comprehensive program and not before exercise can increase force, jump height, and speed.⁸ Athletes who need greater range of motion or need to increase overall flexibility may still benefit from static stretching (Box 33-1). Stretching after activity may also tend to relax the tissues and prevent general postactivity stiffness.

Special considerations must be given to injured athletes with regard to strengthening. Rehabilitation of knee injuries in particular has presented the clinician with a challenge. For example, the main goal of rehabilitation following ACL reconstruction is to restore lower extremity strength while protecting the reconstructed graft and the patellofemoral joint from excessive stresses. Selective quadriceps muscle atrophy occurs following injury and/or immobilization. Strength deficits in the quadriceps of up to 10% have been reported by Shelbourne and associates12 at an average follow-up of 4 years following ACL surgery. Debate exists between the uses of open kinetic chain (OKC) versus closed kinetic chain (CKC) exercises to build quadriceps strength (Fig. 33-1). Several authors have advocated the use of both after ACL reconstruction.^13,14 A literature review by Ross and associates¹⁵ on OKC versus CKC exercises following ACL reconstruction indicates that the greatest amount of ACL strain and patellofemoral joint stress occurs at approximately 40° of knee flexion to full extension.^16,17 It was therefore recommended that OKC exercises for quadriceps strengthening be performed with knee angles greater that 40° to avoid excessive stress on these structures. Closed chain activities beyond 60° were to be avoided since maximum stress on the patellofemoral joint occurs between 60° and 90° of flexion.¹⁷

Because of the predominant atrophy of type I (slow twitch) muscle fibers following injury or immobilization, high repetitions (6 to 10 sets, 12 to 15 repetitions) with low resistance is recommended early in the rehabilitation program.¹⁵ Establishing normal muscle balance for both involved and uninvolved limbs is one of the primary goals. A comprehensive strength training program should address core, hip, calf, and ankle musculature, as well as establish appropriate quadriceps/hamstring ratios. Strengthening of the hamstrings using both closed and open chain methods is important because of their role in assisting in the control of anterior tibial translation. Traditional and functional techniques can be incorporated for both variety and effectiveness (Box 33-2).

There has been an increasing amount of literature in recent years regarding the relationship of hip and core strength as factors in lower extremity injuries. Unfortunately, this relationship is not quite clear. For example, weakness of the hip abductors and external rotators has been shown to contribute to increased hip adduction and internal rotation motion observed in female runners with patellofemoral pain or iliotibial band syndrome. However, it has also been shown that these motion abnormalities can exist even though no strength deficits are present. This indicates an apparent disconnect between muscle strength and observed abnormal kinematics in some cases. Therefore, it has been suggested that additional factors such as altered proprioception and neuromuscular control of the lumbo-pelvic and hip regions should also be considered in the clinical assessment and treatment plan of individuals with lower extremity injuries.¹⁸