Explosive hamstrings strength asymmetry persists despite maximal hamstring strength recovery following anterior cruciate ligament reconstruction using hamstring tendon autografts.

PURPOSE: To investigate the differences in maximal (isometric and concentric peak torque) and explosive (rate of torque development (RTD)) hamstring and quadriceps strength symmetry between males and females during early- and late-phase rehabilitation after anterior cruciate ligament reconstruction (ACLR) using hamstring tendon (HT) autografts and to determine the interaction of time and sex on maximal and explosive strength symmetry. METHODS: A total of 38 female and 51 male participants were assessed during early (3-6 months post-operative) and late (7-12 months post-operative) phases of rehabilitation following ACLR. Maximal (concentric and isometric peak torque) and explosive (isometric RTD) hamstring and quadriceps strength were assessed and presented as limb symmetry index (LSI). RESULTS: Maximal concentric hamstrings asymmetry (Early: 86 ± 14; Late 92 ± 13; p = 0.005) as well as maximal concentric (Early, 73 ± 15; Late 91 ± 12; p < 0.001) and explosive (Early: 82 ± 30; Late: 92 ± 25; p = 0.03) quadriceps asymmetry decreased from early to late rehabilitation. However, there were no significant changes in maximal isometric quadriceps strength and explosive isometric hamstring strength in the same time period. Females had a larger asymmetry in maximal concentric (Females: 75 ± 17; Males: 81 ± 15; p = 0.001) and explosive (Females: 81 ± 32; Males: 89 ± 25; p = 0.01) quadriceps strength than males throughout rehabilitation. There were no sex differences in maximal and explosive hamstring strength. There were no sex by time interactions for any variables. CONCLUSION: Explosive hamstring strength asymmetry did not improve despite recovery of maximal hamstring strength during rehabilitation following ACLR with HT autografts. While sex did not influence strength recovery, females had larger maximal and explosive quadriceps strength asymmetry compared to males throughout rehabilitation following ACLR. LEVEL OF EVIDENCE: Level III.

Proximal exercises are effective in treating patellofemoral pain syndrome: a systematic review.

BACKGROUND: Patellofemoral pain syndrome is a common disorder of the knee with multifactorial aetiology. Multimodal treatment, including exercise therapy, has been shown to be effective in the treatment of patellofemoral pain, although some patients continue to experience pain and dysfunction despite treatment. To address this, recent research has started to investigate the lumbo-pelvic and hip girdle in patellofemoral pain. PURPOSE: The aim of this systematic review was to investigate the effectiveness of proximal exercises, compared with knee exercises, for patients with patellofemoral pain, in improving pain and function. METHODS: A computer-based search (population: patients with patellofemoral pain, intervention: proximal [hip or lumbo-pelvic] exercises, comparator: knee exercises, outcome: self-reported pain and/or functional questionnaire) was undertaken. Medline, Embase, CINAHL, SportsDiscus, Cochrane Library and PEDro were searched for studies published between January 2011 and January 2013. The included studies were appraised independently using the McMaster Critical Review Form for Quantitative Studies. Data was extracted for the exercise prescription and applicable outcome measures, and a descriptive analysis undertaken. RESULTS: Eight studies (three randomized controlled trials, one clinical controlled trial, three cohort studies and one case series) of moderate to high methodological quality met the inclusion criteria. Proximal exercise programs showed a consistent reduction of pain and function in the treatment of patellofemoral pain. Knee exercise programs had variable outcomes. CONCLUSION: Proximal interventions provide relief of pain and improved function in the short and long term and therefore physical therapists should consider using proximal interventions for treatment of patellofemoral pain. LEVEL OF EVIDENCE: 3a.