Neurophysiologic Influences on Hamstring Flexibility: A Pilot Study.

Clinical Journal of Sport Medicine. 11(4):241-246, October 2001.
Krabak, Brian J. MD *+; Laskowski, Edward R. MD ++; Smith, Jay MD ++; Stuart, Michael J. MD [S]; Wong, Gilbert Y. MD [P]

Abstract:
Objective: To examine the potential contribution of neurologic influences on hamstring length during passive range of motion.

Design: Prospective study.

Settings: Academic sports medicine center.

Patients: 15 subjects undergoing arthroscopic surgery for unilateral knee injuries without previous injury to the contralateral knee.

Interventions: Subjects received: 1) spinal anesthesia with bupivacaine, 2) epidural anesthesia with lidocaine, 3) general anesthesia, or 4) femoral nerve block of injured leg only.

Main Outcome Measures: Noninjured leg popliteal angle preoperatively, intraoperatively under anesthesia, and postoperatively after recovery from anesthesia.

Results: The overall mean popliteal angle was 132.5 +/- 3.1[degrees] preoperatively, 134.31 +/- 11.6[degrees] intraoperatively, and 130.7 +/- 10.2[degrees] postoperatively. Overall, the intraoperative angle was significantly greater than the postoperative angle (p = 0.02). The mean change in popliteal angle was 8.1 +/- 2.2[degrees] (Group 1), -0.4 +/- 1.9[degrees] (Group 2), 0.9 +/- 1.4[degrees] (Group 3), and -2.4 +/- 3.8[degrees] (Group 4). There was no significant change in pre- to postoperative popliteal angle in relation to postoperative pain. Females had a greater mean popliteal angle (139.84[degrees]) compared with males (128.84[degrees]) (p = 0.04).

Clinical Relevance: Understanding the neuromuscular influences on muscle flexibility will assist in the development of new rehabilitative and injury preventative techniques.

Conclusion: The present pilot study implicates neural contributions to muscle flexibility. Further studies are needed to delineate the relative contributions of neural and muscular components and to facilitate new techniques in the rehabilitation and prevention of injury.

An unusual cause for chronic pain in the proximal hamstring (buttock) area

Vijay Vad, MD, Assistant Professor in Rehabilitation Medicine, Cornell University Medical College, Hospital for Special Surgery, New York, New York

Hamstring injuries are common in tennis. However, there is a sub-group of tennis players who maybe have a different aetiology of chronic hamstring pain at the muscle-tendon junction. A summary of 12 cases is presented below. All 12 were collegiate tennis players aged 20-22, who presented for a second opinion following extensive rehabilitation (minimum 4 months) for a presumed chronic hamstring strain.

The case histories showed the following characteristics for all of the players. They noted the onset of pain while lunging for a stroke, with the onset of hamstring pain on the ipsilateral side of their dominant arm. None had any low back or buttock pain. The pain at the muscle-tendon junction of the hamstring worsened with continued lunging as well as with bending and prolonged sitting.

Physical examination showed only mild to moderate pain reproduction with deep palpation, as well as with resisted hamstring manual muscle testing. The patients had L5 myotome weakness.

MRI of the lumbar spine was ordered to rule out the lumbar spine as the aetiology of the chronic hamstring pain. MRI showed an L4-L5 disc bulge without any nerve root compression.

The results of nerve conduction studies were normal, but the needle examination revealed spontaneous activity at the L5 myotome of the symptomatic limb.

At this point, the players had a series of L5 selective nerve root epidural injections (Ref. 1) performed under fluoroscopy (average of 1.4 injections, range of 1-3). This was combined with daily use at night of a back cryobrace combined with a 5-stage lumbar stabilisation programme using aqua-therapy (Ref. 2). At an average of eight weeks after the first injection, all players returned to pre-injury level of tennis competition.

Chemical radiculitis

`Chronic hamstring strain’ is actually a chemical radiculitis from an L4-L5 disc bulge. The chemical irritation of the nerve root from the disc nucleus pulposus can manifest itself only at the muscle-tendon junction at times without any back or buttock pain. Increased pain with prolonged sitting can also lead to a suspicion of a disc causing nerve root irritation.

The transforaminal epidural injections under fluoroscopy, which are a much more precise form of the old epidural technique, have the advantage of precisely delivering the medication at the nerve-disc interphase where the pathology lies, while minimising nerve root injury or dural puncture incidence. These more exotic epidurals produced a 75% success rate in a retrospective study (Ref. 1) and 84% success rate in a prospective study at our institution, with long-lasting relief of pain when combined with a precise rehabilitation program.

The goal of rehabilitation is to gradually restore the delicate balance between flexibility, strength and endurance. The rehabilitation programme is carried out in four phases. In the early stages of phase1, aqua-therapy is used in combination with isometric strengthening and stretching. Phase 2 emphasises non-weight bearing, concentric strengthening. Phase 3 emphasises functional weight-bearing eccentric strengthening. The last phase, Phase 4, focuses on sports-specific training.

Ref. 1. Vad, V. et al. Fluoroscopic transforaminal lumbar epidural steroids: An Outcome Study. Arch. of Phys. Med. Rehabil. 79: 1362-1366, 1998

Ref. 2. Vad, V. et al. Segmental instability: rehabilitation considerations. Seminars in Spine Surgery 8: 1-8, 1996.

The Effects of Resisted Sprint Training on Acceleration Performance and Kinematics in Soccer, Rugby Union, and Australian Football Players

Christopher D. Spinks

Strength and Conditioning Department, New South Wales Institute of Sport, Sydney, New South Wales, Australia

Aron J. Murphy and Robert G. Lockie

Human Performance Laboratory, University of Technology, Sydney, New South Wales, Australia

Warwick L. Spinks

Human Performance Laboratory, Institute of Sport and Exercise Science, James Cook University, Townsville, Queensland, Australia

ABSTRACT

Spinks, C.D., A.J. Murphy, W.L. Spinks, and R.G. Lockie. The effects of resisted sprint training on acceleration performance and kinematics in soccer, rugby union, and Australian football players. J. Strength Cond. Res. 21(1):77–85. 2007.— Acceleration is a significant feature of game-deciding situations in the various codes of football. However little is known about the acceleration characteristics of football players, the effects of acceleration training, or the effectiveness of different training modalities. This study examined the effects of resisted sprint (RS) training (weighted sled towing) on acceleration performance (0–15 m), leg power (countermovement jump [CMJ], 5-bound test [5BT], and 50-cm drop jump [50DJ]), gait (foot contact time, stride length, stride frequency, step length, and flight time), and joint (shoulder, elbow, hip, and knee) kinematics in men (N = 30) currently playing soccer, rugby union, or Australian football. Gait and kinematic measurements were derived from the first and second strides of an acceleration effort. Participants were randomly assigned to 1 of 3 treatment conditions: (a) 8-week sprint training of two 1-h sessions·wk⁻¹ plus RS training (RS group, n = 10), (b) 8-week nonresisted sprint training program of two 1-h sessions·wk⁻¹ (NRS group, n = 10), or (c) control (n = 10). The results indicated that an 8-week RS training program (a) significantly improves acceleration and leg power (CMJ and 5BT) performance but is no more effective than an 8-week NRS training program, (b) significantly improves reactive strength (50DJ), and (c) has minimal impact on gait and upper- and lower-body kinematics during acceleration performance compared to an 8-week NRS training program. These findings suggest that RS training will not adversely affect acceleration kinematics and gait. Although apparently no more effective than NRS training, this training modality provides an overload stimulus to acceleration mechanics and recruitment of the hip and knee extensors, resulting in greater application of horizontal power.

A Multidisciplinary Approach to the Evaluation, Reconstruction and Rehabilitation of the Multi-Ligament Injured Athlete

Department of Orthopaedics & Rehabilitation, Yale University School of Medicine, New Haven, Connecticut, USA.
Knee dislocations with multi-ligamentous involvement are potentially limb-threatening injuries that require extensive surgical and rehabilitative intervention. These knee injuries, such as combined anterior cruciate ligament, posterior cruciate ligament, medial collateral ligament and/or lateral collateral ligament injuries, are devastating injuries with results that vary from total disability to nearly full recovery of function. Recent surgical advances, including the use of allograft tissues, have increased the efficacy of these procedures while posing new challenges. By combining scientifically based surgical and rehabilitative approaches, improved outcomes in these difficult cases are being reported in the orthopaedic literature.This review details the epidemiology and biomechanics of these serious knee ligament injuries. In addition, state-of-the-art surgical and rehabilitative techniques will be outlined. Clinical and diagnostic imaging evaluation of these knee injuries is reviewed in order to plan and execute the surgical and rehabilitative practices. We review the basic science, surgical and rehabilitative theories and practices associated with bringing patients with these serious knee injury injuries to full recovery, and detail the development of strategies for developing protocols to address these complicated cases.